Differences in the L98 heads
#1
Differences in the L98 heads
So from advice from a people here and other venues, as well as a ton of reading it looks like for my setup the l98 heads are the best choice. My deal now is that I am having a difficult time distinguishing the differences in the many types of L98 heads.
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there was;
On the firebirds/camaros
iron 305 heads from 85-86
iron 305 heads from 86-89
iron 350 heads from 87-89
iron 350 heads from 90-92
on the corvette
iron 350 heads from 84-86
aluminum 350 heads from 87-89
Aluminum 350 heads from 90-92
-----------------------------
This gives me waaay to many choices.
This is for an 86 camaro intake and I am unclear if I can use the 87 and newer style heads for one, and to be blunt what they all flow like and their valve size and combustion chamber size.
Can someone shed some light on these for me?
----------------------------
there was;
On the firebirds/camaros
iron 305 heads from 85-86
iron 305 heads from 86-89
iron 350 heads from 87-89
iron 350 heads from 90-92
on the corvette
iron 350 heads from 84-86
aluminum 350 heads from 87-89
Aluminum 350 heads from 90-92
-----------------------------
This gives me waaay to many choices.
This is for an 86 camaro intake and I am unclear if I can use the 87 and newer style heads for one, and to be blunt what they all flow like and their valve size and combustion chamber size.
Can someone shed some light on these for me?
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Re: Differences in the L98 heads
considering that you have a 86 camaro going with the 58cc vette l98 will give you the best results...... they are not that much better than the iron l98 but the iron l98 heads have 64cc chambers while the vette l98 have 58cc which would give you more compression...... the vette l98 heads all use the older style intake pattern so it will work for your car.... idy say that the l98 vette heads are a nice upgrade for a 305 thirdgen.....
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Re: Differences in the L98 heads
283 block
The ones to get would be LB9 (305) heads. These will be iron, and 58cc.
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Re: Differences in the L98 heads
running a blower on the 283
Meanwhile, given that the short block is probably the TINIEST part of THE WHOLE cost of such a project, seems kind of ..... short-sighted ..... to handicap yourself with that few CID. THINK: you could spend 5% more, but get 25% more for your money, with a larger motor. How is it then a good idea to NOT spend the extra 5% on a different block?
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#8
Re: Differences in the L98 heads
It'd be worthwhile to mention details like that up front. Makes the advice more nearly applicable. (or not)
Meanwhile, given that the short block is probably the TINIEST part of THE WHOLE cost of such a project, seems kind of ..... short-sighted ..... to handicap yourself with that few CID. THINK: you could spend 5% more, but get 25% more for your money, with a larger motor. How is it then a good idea to NOT spend the extra 5% on a different block?
Meanwhile, given that the short block is probably the TINIEST part of THE WHOLE cost of such a project, seems kind of ..... short-sighted ..... to handicap yourself with that few CID. THINK: you could spend 5% more, but get 25% more for your money, with a larger motor. How is it then a good idea to NOT spend the extra 5% on a different block?
#9
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Re: Differences in the L98 heads
All 86 and earlier intakes should use the old-style bolt pattern (all 6 bolts on each side are at the same angle). 87 and later the 2 center bolts on each side are "stood up" at a steeper angle. Should be obvious which intake you have just by looking at those 2 center bolt holes.
Now, compression and engine specs aside, there really weren't any commonly available 64cc heads prior to the 1987 Camaro/Firebird L98 TPI engines. At least not unless you go way back to the early 70s before the "emissions era" of low compression engines. All F-body (cast iron) L98 TPI heads are of the later 87-up bolt pattern, therefore, and they're really one of the few heads you'll find with 64cc chambers that were made in any quantity around those years.
As you see above, aluminum Vette heads have the right bolt pattern to work with an 86-down intake, but they also have smaller 58cc chambers. And any head off a little 305 will also have chamber sizes in the 56-60cc range, with 58cc being most common.
Those earlier cast iron Vette L98 heads (before they went to aluminum) I don't have any experience with (I don't know their specs) but I am not sure how easy they will be to find. They certainly didn't use them on more common high-poroduction vehicles like pickup trucks with 350s under the hood.
So if you're after 64cc heads with an old 86-down bolt pattern you're actually not going to find much from the factory. Aftermarket heads with 64cc chambers and old-style bolt pattern are, of course, more common than dirt, but not so much with factory stuff.
Now, compression and engine specs aside, there really weren't any commonly available 64cc heads prior to the 1987 Camaro/Firebird L98 TPI engines. At least not unless you go way back to the early 70s before the "emissions era" of low compression engines. All F-body (cast iron) L98 TPI heads are of the later 87-up bolt pattern, therefore, and they're really one of the few heads you'll find with 64cc chambers that were made in any quantity around those years.
As you see above, aluminum Vette heads have the right bolt pattern to work with an 86-down intake, but they also have smaller 58cc chambers. And any head off a little 305 will also have chamber sizes in the 56-60cc range, with 58cc being most common.
Those earlier cast iron Vette L98 heads (before they went to aluminum) I don't have any experience with (I don't know their specs) but I am not sure how easy they will be to find. They certainly didn't use them on more common high-poroduction vehicles like pickup trucks with 350s under the hood.
So if you're after 64cc heads with an old 86-down bolt pattern you're actually not going to find much from the factory. Aftermarket heads with 64cc chambers and old-style bolt pattern are, of course, more common than dirt, but not so much with factory stuff.
Last edited by Damon; 07-20-2011 at 07:03 PM.
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Re: Differences in the L98 heads
For $350, you can easily get a 400 short block core.
For $250 less, you can easily get a late-model 350 short block core.
Not sure who would pay money for any of that old stuff; including that sort of thing in your thinking is .... wishful, at best.
The small motors still don't make sense.
If you're going to spend $5000 on a motor, which you WILL from drive-in to drive-out, the difference in the cost of the short block to go from some old garbage bottom-feeder "save money" thing, to the best you can possibly get, is probably less than the cost of your INTAKE TUBING. Let alone, anything substantial. IOW, for what you'll spend on PAINT, you're going to short yourself a SUBSTANTIAL amount of power. If you were to look up "penny wise and pound foolish" in the dictionary, you might even find them using this as an example.
For $250 less, you can easily get a late-model 350 short block core.
Not sure who would pay money for any of that old stuff; including that sort of thing in your thinking is .... wishful, at best.
The small motors still don't make sense.
If you're going to spend $5000 on a motor, which you WILL from drive-in to drive-out, the difference in the cost of the short block to go from some old garbage bottom-feeder "save money" thing, to the best you can possibly get, is probably less than the cost of your INTAKE TUBING. Let alone, anything substantial. IOW, for what you'll spend on PAINT, you're going to short yourself a SUBSTANTIAL amount of power. If you were to look up "penny wise and pound foolish" in the dictionary, you might even find them using this as an example.
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Car: 1988 Flame Red Trans am GTA
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Axle/Gears: ls1 torsen 3.42 gear
Re: Differences in the L98 heads
shoot for 100 you can have my old l98 block..... like everyone is saying for a few hundred bucks you can get a 400 block and gain 117 cubes, thats almost 1.5 times bigger than that 283 block.. seems like a silly reason to still use a 283 considering you can get much bigger blocks for only a few bucks more.... just something to think about....
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Re: Differences in the L98 heads
shoot for 100 you can have my old l98 block..... like everyone is saying for a few hundred bucks you can get a 400 block and gain 117 cubes, thats almost 1.5 times bigger than that 283 block.. seems like a silly reason to still use a 283 considering you can get much bigger blocks for only a few bucks more.... just something to think about....
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Re: Differences in the L98 heads
I love threads like this... I agree with u sofakingdom on this one though!
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