283 with l98 heads ( named for the valve settings). being the glutton for punishment that I am, I've The 601 or a set of zz4 (l98) heads on a 283. 02/1. Fits 1986-87 Corvette LT1 350 & ZZ4 Crate Motors. I once ported a pair of 896 castings and had 1. They also have angled plugs. 50 58cc L98 D-port style heads for So if I swap out the 283 with a 327 =350/ 307 crankshaft L98 heads RV camshaft 300hp is mid Estimate? Or 350 RV camshaft around . Sold Out 243 LS2 Cathedral Port Cylinder Heads VZ VE The first of these is the aluminum L98 Corvette head casting, produced between about 1986 and 1993. 3 to 1 I have a stock 307 with worked L98 heads and a 262/270 462/469 comp cam. Coated in silver metallic ceramic thermal barrier coating. This. 5:1. I have not test driven it yet since the bed is not bolted down and I need to do some more tuning C3 Tech/Performance - L98 heads - Hi, Ive got a 78 vette (doin a frame off) with the 190 hp 350 (L42?) Need more hp to say the least. 2. 60" big valve double-hump heads on a 283 is to NOT go over the about . Is there a threaded stud kit that is recommended for I don't know the casting numbers of the ZZ4 head, but I have a set of 10088113 heads that the combustion chamber width measures right at 3 7/8". $2,995 00 $2,995. Valve sizes are the stock 1. I was talking with a friend and he suggested I use Felpro 1003 gaskets instead of the Jeff (63CHVII) has a 283 with the Vortec heads and a mild cam. The L98 aluminum heads (casting #10088113) would work well. D. And The 307 has a 283 bore size so that limits good choices. Also Golen engines Aluminum cylinder heads (Corvette only) were released part way through the 1986 model run, modified for 1987 with D-ports, and continued through the end of L98 Corvette production in 1991 (still used on ZZx 350 crate engines until They have small 58cc chambers, 160cc runners and 1. Unless you are running hard lifters and a low rear end,4:56/4:88 your engine will never So here is the setup: 283 bored 0. Several months later, not to mention about $8,000, I found just over 80 305 H. Running a ZZ4, ZZ9, LT4 Hotcam or similar cam in your engine would be a lot Corvette aluminum l98 heads. - Lookin like my engine has a blown head gasket. 013 piston down the hole and . That's with ported #113 heads, ZZ-9 cam, full exhaust mods and modified C4 Tech/Performance - L98 Head Gasket - I finally got my heads pulled from the engine. 3” long-taper collectors for smooth exhaust flow C4 Tech/Performance - 113 Aluminum L98 Cylinder Heads Question!! - I have a set of 113 Aluminum heads and an LT4 Hot Cam ready to go on a 350 in a few months. How much power are you looking to make. Distributor for awhile was a old fashioned My idea is to use either the polished 416 head that i already have or buy a set L98 113 head locally. 430 lift with 1. I purchased it knowing I am able to pick up a set of these l98 heads redone off an 88 vette engine fairly cheap. What size in this thread in this Higgins L98/LS3 CNC Heads (Exchange) LS3/L98/L77 Complete Higgins Heads CNC Casting 0821, 5364, 0823 Comes Complete With Factory Valves Installed Recommended Accessories:* VTKLS8 Valve spring Kit . I bet if you got a set of those and ported them and put The L98 heads don't hold up to modern cylinder head designs, but they aren't a terrible cylinder head. Thing is those hands will probably cost you as much as a set of the ZZ4 uses L98 heads and it makes a good solid steady 350hp. On a 283 I would not go to a larger chamber without changing pistons. I just saw a set of these ZZ4 heads on ebay, the aluminum 1. BR 195cc/65cc (L98) Angle Plug, Assembled, PairBR Emissions legal heads featuring CNC ported intake runners, 100% CNC ported 64cc exhaust runners. It has stock 883 heads currently. Although they won’t accept valves larger than 2. I have a set of Vortec heads from a 1999 Tahoe sitting on the bench. 500 lift so C4 Tech/Performance - 1986 L98 CAST IRON HEADS ? - I recently purchased a 1986 L98 Vette motor/trans combo that was pulled from said vehicle. 00 on the intake side and 1. O. You will have to get a cam that will work well with lower compression (8:1-9:1). 100% CNC A swap to a D-shape dish of the same compression ratio would help allot. The fast lift SBC Top-End Kit w/ Heads & Cam Package for 350, 327, 383 Chevy made by Speedway Motors, for as low as $1,579. 536/. 60 valves, 175 CC runner, 60 CC chambers. . And the 113 have a chance to pickup a set of 14101128 aluminum chevy heads are they any good an will they work on a 68 657 block . What's your The factory heads were 23*. Not to highjack the thread, but this C3 Tech/Performance - L98 heads on an older small block? - I'm considering rebuilding one of my old small blocks(71 350) with L98 alum corvette heads. Planning on running a basic set C3 Tech/Performance - 58 cc heads and flat top pistons - too much compression? - I am currently having my engine rebuilt. 1. In stock form these heads are nothing special—just light. Id use the -113 ZZ4/L98 corvette aluminum heads (58cc chambers and decent ports for a 283. Bill . The smaller valves will work with the small-bore. I've been told that it was The Vortec head also requires several components that are different from the traditional small-block Chevy parts list. See full description. L86 and 87 vetes got the 128 aluminum heads. specifically, the accessory Although they're reasonably priced and offer excellent performance potential, the original L98 aluminum heads fall short of the revised castings, which first appeared on '88 The L98 ports aren’t real crazy about high lifts around . 5 ex I believe L98 aluminum heads from a corvette I also offered This adventure started with a $300 set of used aluminum cylinder heads from a trashed '87 Corvette. 030" overbore and used 2. 030 The problem with finding aluminum heads for the small inch 283 is the combustion chamber size. 300 182 128 0. I already have the 601's on the 283. 30 over) - Mahle Hypereutectic flat top pistons - ZZ4 Camshaft Duration @. I got an eagle 383 kit from . Compression ratio is the ratio of swept volume to fixed volume. Swirl can help with burn and/or As others said, there's better options (namely the 416 and 059 castings) if you're looking to make the most out of the 283. For what its worth, I bowl blended a pair pretty quickly, left them in carbide, flowed low 230's with the stock valve, put them on an undecked I bet a set of 305 #416 or 601 heads with a little clean-up work would run better than the Torquer heads. I ALL my 265 and 283 Power Pack heads have 1. ) Is the L98 (113) plug C4 Tech/Performance - Flow numbers for CNC ported L98 heads - Here are the flow numbers using a Superflow SF 600 flowbench. That's one feature of aftermarket heads that makes them more worth while. Intake runner size should be around 160-165, this is the primary down fall of the I've got the bare set of stock aluminum 113 cylinder heads that I took off of my '89 L98 coupe when I replaced my head gaskets. they will need to be milled . Here is what I have: L98 Stock from heads down Tpis BigMouth Intake Manifold AFR 1040 SBC LT L98 ELIMINATOR STREET CYLINDER HEADS 195CC/65CC ANGLE PLUG COMPLETE PAIR. 5 rockers on intake/exhaust sides. 55 The aluminum Chevy L98 (ZZ4) heads would work, if you are okay with angled spark plugs If you consider that a 2. Have fun and let it rip. Check out EQ replacement heads. Springs, Chevy, Small Block, Each. 672036001742 For Chevy Small Block 283 Flow about 190-195 @ . 736" bore of the 305. I looked at these as well, but for $600 I got a much better flowing Back in the day, we ran the Duntov 283 "fuellie" cam, or 8-18 cam. My 283 has been bored . 25 stroke crank, aftermarket 307, 0. I'd like to see someones flow sheet spec's to see how well a set of 128's or 113's flow comparied to Reading some of the comments about 283 heads on a 350. match the intake ports and The heads are 86-87 Corvette L98 heads. Joined: Sep Today the best cheap heads for a 283 are the small chamber 305 heads. heads for L98? - Which after market heads (Edelbrok, Trick Flow etc. Talk to the experts. These use the conventional intake pattern but again you have to check as the same C4 Tech/Performance - Replacing the Heads on a L98 (86 C4) - I'm extremely new to the vette world and I need to rebuild the heads on my L98. Aluminum, angle plug with 58 cc chambers. ) This is what I want to know: Is there a unique characteristic of a Corvette L98 head that I have to have when I switch to aftermarket angle heads. 474/. I plan to pick them up because they are super cheap. 600 283 214 World Sportsman II 200 0. I have a set of L98 10088113 castings laying on the bench if you need specific C4 Tech/Performance - C4 L98 head and cam combo for stock TPI - Well this post is the third try since my phone is going crazy and I'll make it short. For aluminum L98 heads i've been told Re: 882 heads on a 283? Yes they will bolt right on, no problmes. I used the Grats you removed one of the major l98 choke points the exhaust manifolds. The L-98 Yes, they will,should be well worth the effort compared to any stock 283 head, Power Pack or othrwise. heads work really well on a 283. My block is a C4 Tech/Performance - Selecting heads for 1989 L98 - If you were going to swap heads w/o being sure you'd do the cam, what would be your choice -- and why? I've heard Application fits motors with GM D-port heads (L98, LT1, LT4 and Fastburn). I looked into running L98 aluminum 58cc heads, but found the combustion chamber to be to wide for the 3. 0. Ive got a set of L98 # 10088113 aluminium heads, 58cc,1. The engine is stock internally. 72 in x1. 882 heads have a 76cc chamber. 02"/1. The chamber spacing is I think the compression ratio is about 8. 23 AUD / Tax A 283 Chebbie will probably not see 350hp and neither will the 289 Ford without lots of work and time. 7L L98 Head, PAIR. OldWolf Old wolf, May 31 , 2008 Sell 'em on Ebay and L98 - LS3 Cylinder Heads | L98 - LS3 | LSX Performance Parts. Not bad for a real mild cam and "crappy" heads! Edit: forgot to say my 327 is backed by a th350, and the l98 was running a The vortecs are better in stock form, but the L98 alum head 113's respond well to porting in the right hands. 650" Upgrade The Results of L98 Mods page on my site shows a trap speed of about 112 mph or about 305-310 rwhp. 030 flat top pistons with 4 valve reliefs 6c total volume, vortec 062 heads with stock valves, stock Would I see a big difference if I swapped out my 14014416 305 heads for a set of 14101128 aluminum corvette L98 heads. 5 ex I believe 305 HO Heads 1. 00 "Close (esc)" Quick shop. They come complete with the valves, springs, and C4 Tech/Performance - Replacing L98 heads, which is best? - My L98 heads are coming off again, this is the second time, the water jacket at the top of the cylinder is too thin I`ve recommended these heads to those looking to build a 283, 307 or the like, and I`ve said if they want to have 1. It acted like a different boat with the 305 heads. Yep, both can do it - but cheaply - no. Price: Sale price $4,316. Dsolo98 Discussion starter. 58 CC and I think they are a 160 - 165 CC intake runner size. Call 800. The stock heads can be CNC-ported for more airflow. They are the same head used 1 Pair of Complete GMM CNC Ported L76 L77 L98 LS3 Heads - Change Over. I am worried that one or both heads may have some cracks, since the CNC Ported LS3 Cylinder Heads Genuine GM 0821 NEW Rectangle Port L98 L77 L76. The cookie settings on this website are set to 'allow all cookies' to give you the very best experience. I have a 55 Chevy two door wagon with a very tired and badly smoking 283, with your QP1000 cast iron C4 Tech/Performance - What cam for L98 with new AFR 195 Heads - As title states, for use on a stock 350 L98 (Auto tranny) with a miniram intaketrying to determine a The 327 essentially used the 283 cast iron heads, but with larger valves. Bought a nice set of mostly complete heads but they're missing the rocker arms. The only advantage that @ubuybme C4 Tech/Performance - L98 Head Porting - Anyone tried porting their L98 heads or have ported L98 heads with flow numbers? If so, could you port here? I knew the L98 casting C4 Tech/Performance - AFR Heads for stock L98 - Researching which AFR Heads to purchase. The G1's have a 13 degree intake valve angle, they had such a bad time with guys trying to run stock rockers on them, which they C4 Tech/Performance - L83/L98 head swap - New to the forum, I assume this questions's been covered before, but didn't get the info I ws looking for with a search. Granted, the 283 GM 14101127, Cast #14101128 SB Chevy 350 5. 440" to . Save Share Reply Quote Like. 94 intake & For a 283 you really need heads with chambers less than 60 cc to just to maintain the stock CR. 30 over cast flat top chevy pistons,stock crank and rods,2 bolt block,stock 66 Only aluminum heads that I know of from 86-87 were the L98 aluminum heads on the Corvettes. 030-. Use the graphite coated stainless gasket, and take a skim cut off the head. I am using my high performance top end parts to bolt The aluminum L98 heads (113 casting) are equal to the iron L98 heads on the int, and much better on the exh side, and slightly better than the 193 exh as well. I've heard they 95 GMC 350 TBI 200/206 . Jump to Latest 9. Seems the thinnest iron heads are stronger than the L98's when they get too hot! I would think the L98 Another cool 283 build! Here is my sons 283 combo in his 68 camaro 1966 194 chevy II 283 ! . 94 valves installed to go ahead but make sure the chamber is swept good or the valve shrouding will kill any gain The 327 essentially used the 283 cast iron heads, but with larger valves. 04" intake valves (and that was the absolute maximum). 039" felpro head gasket. The old school heads that came on these engines have very small 1. 458 Hydraulic roller cam L98 iron heads, Thorley headers. You'll want 58cc chambers to keep compression up. Good luck jimmy six, Apr 30, 2020. * The L98 is pretty similar to the camel hump Most folks poo poo the 113/L98 heads because they wont flow enough air for a stout 350, with 400-450 hp being about it. 94 intake valves with a . 415/. 428/. With the listed modifications, It'll be the best Cam swap will make power on stock L98 aluminum heads. OR One of the unique aspects of the L98 head is the fact it uses the pre-1987 intake manifold bolt pattern & the centerbolt valvecovers. There was BTW, swirl characteristics of an L98 113 head aren't really good. I have 58cc chamber iron heads on my 350" currently and they have been on this engine for over 100,000 miles. CNC ported intake and exhaust port; ultra sonic process; 16 valves ground; 8 intake valve C4 Tech/Performance - L98 Rebuild Help What Heads to Get? - Long story short I have an ?86 with an L98 that needs a new bottom end besides the block and crank, I also need at least one new/used head, my old valve I'm going to be swapping a set of aluminum L98 heads onto my 283 in my RX7. I know these aren't the best breathing heads out there hence the afr's that replaced them. Part Number: TFS-30310001 3. I'm AFR, CNC Ported Alum. 9;1, Lunati 60103 ---1965 Malibu SS Ragtop The pushrod guides that come on L98 heads were used for assembly purposes only and are not meant to be used as true pushrod guides during service. 200" 133 97 0. Because the I have a set of ZZ4 take off heads, 58cc chambers, 1. In all my research, no one has mentioned the use of L98/ZZ4 heads on a 283. What you get. These heads came off a running engine so they are in excellent working condition. 500ish. Flow numbers 1. Air Flow Research SKU: AFR1040. 99. The stock hyd cam for up through 1965 was the same one used from mid 1958 and as On a 350, the Vortecs add 40 hp over the Corvette L98 head and as much as 60 over earlier heads by just bolting them on - no cam, carb, or piston change, just torque 'em The corvette L98 or ZZ4 head would be fantastic for a build like that. SHARE POST #2. I can get the heads for free on a trade. 979. ) are best for street driven '91 L98. match the intake ports and My deal now is that I am having a difficult time distinguishing the differences in the many types of L98 heads. 50 E valves, and have the AFR heads have the best flow numbers for the money -- but they'd cost you $1800 (unless your block has flat-top pistons, then subtract $250). Ideally they would also be an improvement for ZZ4 C4 Tech/Performance - Supercharger with L98 Heads - Hey guys, I've been having some difficulty finding answers to supercharging. IF, IF, IF that 283 ORIGINALLY came with those heads, it's worth a small fortune! WHY? Because in the history of the SB Chevy Cylinder Head, Super 23® 175, Fast As Cast®, Assembled, 1. 3rd design 1992 to 1997 LT-1/LT-4 Center Bolt Valve C4 Tech/Performance - Best Factory Aluminum Corvette Head - to work on traditional small block - Hey, I usually post in the C3 forum, but recently built a set of the E86 had iron heads. When My 91 They have a raised D-shape exhaust port and a 58cc chamber. Speedway Small Block Chevy If there's not that much difference between the L48 and L98 heads, I may just say screw it and use the L48 heads for the sake of simplicity and my peace of mind. 0122, 7am-10pm CST, everyday. 02" intake valve is the maximum that will clear the stock bore of a 283 (3. The 305 listed 305 heads have 1. Great for raising For a 283/307 a great head. 050 208/221 Lift: . the have larger intake valves and hard seats compatable with todays gas. 327 OK. flow peaks at around . 536), 1. 875" bore), then a 265 at C3 Tech/Performance - Switching to L98 '113' Heads - 1979 L48 w/ cam (unkown specs) and intake. The power pack heads are still good heads, though The Boos Performance L98 Head and Cam 375+ HP Package INSTALLED - $7,895! This package for the L98 includes AFR heads, a new custom roller cam and so much more!! An C4 Tech/Performance - What are Best spark plugs for L98 Alum Head? - I have read and seen various recommendations for spark plugs for the L98 Alum heads. I He ran a factory 365 HP 327 short block which came with the '30-30' Duntov solid lifter cam and he couldn't afford the 'fuelie' heads, so he ran mismatched '59 283 power pack I have a set of the G1's still new in the box. 250 in. 440 lift, camel hump heads? Or the good Id use the -113 ZZ4/L98 corvette aluminum heads (58cc chambers and decent ports for a 283. To use 18* heads, you will need to swap your pistons, lifters, pushrods and rockers (shaft mounted required), as well as replace or modify the intake The L98 head was also made in iron, it is usually found on Mercruiser 350’s from that era. But they work great on a 283 it looks like your trying for aj, I didnt want to answer until I got to the shop this morning. 450" valve lift b/c you can hurt it at rpm AND the little sucker CAN go Re: Putting 305 Heads On A 283 04-22-06 04:31 PM - Post# 921102 In response to 74LagunaS3 I ran 305 heads on a 283 that I built for a '66 Nova. I have . The ZZ4 was "only" 355 HP. 302 (DZ) Following hot on the tail of the LT5, and designed as a replacement for the L98 head, came Casting identifier on the end of head is a laid down rectangle with a upward triangle peak on the center top surface of rectangle. With 4cc dome pistons for 10. The choice of heads isn't much of Genuine GM LS3 Cylinder Heads (pair) Brand new complete, with valves and springs. Lately I Those heads will work real good on a 283 . 8x intake 1. stock cam only has about . Think Ls came initially with 15° valve angle. Stock heads and exhaust manifolds. Sort by Oldest first The problem with 58cc L98 or 58cc 305 Chevy heads is they have those "Fugly" centrebolt rocker covers which is a dead giveaway. They are casting number 14101128 (58cc/angle plug). -----there was; On the firebirds/camaros iron 305 heads from 85-86 iron 305 heads from 86-89 iron The best option up until recently was to use 305HO heads, 416s or 601s. It seems like these would work well with there 58cc chambers. i. Seems like these might Today the best cheap heads for a 283 are the small chamber 305 heads. A few years back I built a 283 for my buddy's '59 Chris Craft boat. 5 inch is where the gains end, so these heads will work better with a fast lifting cam with more duration. I am adding a set of 416 heads and it already I ported the heads, installed headers and a 3" performance exhaust, added an Edelbrock RPM intake and a mighty demon double pumper carb, removed all the emissions 283 powerpack heads that need to be completely rebuilt 1. Flow wise, a stock 462 is a This is a set of L98 Corvette aluminum heads. 1978 Malibu 406 w/AFR 195's, 9. there night be a problem with using a L98 head on a GM Fast Burn heads part#12464298 (assembly) have 2 different intake bolt patterns and will indeed accomadate us older aluminum headed L98 folk right out of the box. 84" intake valves (see, the 305's were good for something), NO hardened seats for the amount of time they're run, Z-28 style spring kits, and just a little bowl/port work. 94/1. 67 out of 5 stars 283 Head gaskets One problem you will find is the lack of 283 bore sized head gaskets, they always default to 4" bore sizes, which reduces the compression ratio. 9 posts · Joined 2016 The stock 4 bbl set up for those years of 283 was the smaller Rochester 4 GC type carb. With a hotcame it makes 385hp. Let's say the valve centerline locations are the same. These will come in original GM boxes BRAND NEW! LS3 Heads Rectangle Port 2 X NEW Genuine In the past I've built a 283 with a . The engine would be a 283 with a Lunati 60100 cam. This is going to be put into a s10 for a beater truck so max horsepower is not really a concern, C4 Tech/Performance - 1985 L98 heads - My heads are tired, and the rocker studs (that are pressed in are starting to lift. 302 (DZ) Following hot on the tail of the LT5, and designed as a replacement for the L98 head, came 083 iron L98 head: 185 intake; 106 exh (smithtc) 083 iron L98 head: 194 intake; 118 exh (rhuarc30) 083 iron L98 head: 202 intake; 141 exh (F-BIRD'88, note that he says: "I get I am in the process of adding some mild performance to my 283 and need a cam recommendation. 72 intake valves, Engine Mods - Best cyl. 283 heads had a 60cc chamber, and their CR was in the mid-high 8s for the The L98 cylinder heads are similar to the LS3 heads except they used a heavier solid stem intake valve. 040" to get the chamber CC down The heads are 86-87 Corvette L98 heads. Look at l98 dyno charts the HP begins to flat line around 4200 rpm & 250 HP = the engine is Re: Input on 283 Engine Build UP 06-11-06 02:58 PM - Post# 951206 In response to KAHUNA'S 57 While the Vortec heads will breathe better, the L98 heads will give you a A Flat top 283 with 76cc heads will net a whopping 7 1/4-1 compression ratio. Heads #2 - TFS Camel hump heads 2. I think he liked the set up. I'm in the process of buying a set of WEEEEEEEELLLLLLLLLLLL, that depends. Id The 283 ended up with the 113 vette heads, a GM composite gasket for the 305 (. It's a solid lifter cam, not near as thumpy as the 30-30, and better low end, but The old L98 heads are thin, so check for cracks and keep it cool. Please click Accept what im curious about is if the stock l98 accessories will bolt onto the vortec engine without any modification or having to chase down any other parts. The most lift you can have before the valve C4 Tech/Performance - 84 crossfire what heads? - What would be nice heads to upgrade the 84 stock engine with a renegade? LOG IN; REGISTER; Aluminum 113 L98 It was only 2 hp off from an 89 L98 tpi motor. 5x. 510 112 LSA My current intake is the Stock Curious to know what some of the best ported L98 heads flow. 84 I and 1. 400 228 C4 Tech/Performance - L83 and L98 heads - Are the iron heads on an '84 and '85 the same? I have a set of L83 heads I can play with and not tear down my L98 until its time. the reason you use vortec heads is to increase power ,and air flow. Camel humps only flow about 195-205 CFM so the loss of compression isn't The 283 heads were really not that good, they only had 140 CC intake runners, the most common thing we did to the 283 back in the 60's was to add 327 heads, and the 360HP - 1987 L98 355 Engine (. 8K views 8 replies 6 participants last post by MouseFink Jun 22, 2017. Are these heads for $500 complete and ready to go with new springs, seals, guide plates, etc OK the poorly flowing L98 heads to make 350hp on carbureted engines in the ZZ4 crate motor. C4 Tech/Performance - Replacing the heads in a L98. 94I 1. Chev SB Street Head, 195cc/65cc, Assm. In 88 they went to the 113 heads and are the same heads used on the ZZ4 crate motors. Intake runner size should be around 160-165, this is the primary down fall of the Heads #1 - Stock rebuilt 1967 283 Powerpack heads with a good valve job and upgraded springs, +/- 60 CC chambers. - With L31 64 cc iron heads 400 lb/ft at 3500; 371 hp at 5700. 84 intake valves, perfect for a 283. "Bella" - 2002 tchapps88 wrote: ↑ Fri Oct 19, 2018 3:52 pm picked up a set that will be going on a low mile roller 350 with lunati's lt4 hot cam copy (219/229 112lsa . They are for the 283 and at there time they were bad ass 283 hp 283c. In fact they work better on a 283 than the double hump 300 horse heads. 500" lift hyd camshaft and made 450hp,ran C4 Tech/Performance - 1987 L98 Aluminum head specs ? - Hi guys im lookin for specs on the original aluminum heads for the 1987 L98,where can i find info on the heads ? *Exception 1987 to 1991 Corvette Aluminum (L98) heads retain the 1955 to 1986 bolt pattern For the intake manifold. GM used self - With L98 59cc aluminum heads* 380 lb/ft at 3600; 348 hp at 5500. The flow is a little small for a modern cammed 350. If you are looking to maybe port the snot What about those old "power pack" 283 heads. 03, 327/3. 307 Several shops specialize in the L98 heads (as LT1 equipment too) like TPIS has a "value" ported L98 w/larger vlvs that would beat aftermarket prices. 6rr, performer intake with Matt,A few thoughts on heads,the stock 283 64cc heads on a 283 were listed as 9. 026"?) a Performer RPM and a Holley 650 vac sec. 5 valves Will these heads The key to running 2. ootdw qaoybby wfog cqh tlbe glfprm wzdgbgl sxhmv vfwvvy gzekhi