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l98 heads?

30K views 8 replies 4 participants last post by  TANGO 
#1 ·
Could anybody give me some info on 87 iroc l98 heads that came off a tpi 350.

Like chamber size and how good they flow.
 
#3 ·
TANGO said:
I used a Set of them #083 TPI Heads on this 350 Build . They are 64cc Chambers with 1.94"in and 1.50"ex Valves . Pre-Vortec Performance Heads . I would say they are good Street Heads for a 350 350 H.P Build .




Thanks for that info, I might buy a set off an 87 iroc.

will they bolt up to my gen1 350 intake?


that motor sounds mean. :D
 
#4 · (Edited)
I think you'll find that L98 aluminum heads have 58CC combustion chambers.
Be careful that they don't raise your compression ratio too much.
Copied & Pasted from the ZZ4 specs on Summits website:
"cast aluminum 1987-91 Corvette L98 cylinder heads. Which have 58cc combustion chambers, 163cc intake runner volume. They have a 1955-86 bolt pattern"
So, yes, your intake should bolt right up....JA.
 
#5 ·
johnnya said:
I think you'll find that L98 aluminum heads have 58CC combustion chambers.
Be careful that they don't raise your compression ratio too much.
Copied & Pasted from the ZZ4 specs on Summits website:
"cast aluminum 1987-91 Corvette L98 cylinder heads. Which have 58cc combustion chambers, 163cc intake runner volume. They have a 1955-86 bolt pattern"
So, yes, your intake should bolt right up....JA.

what do y'all think my compression ratio would be with flat-top pistons?
 
#6 ·
The aluminum ones are 58cc as stated. Ratio will depend on more than just a flattop piston. The combo i was going to run (now for sale), was the aluminum heads, 28cc dish KB piston, Felpro race gasket (dont remember the part#) and the 383 scat crank with 5.7 rod. This put me at about 9.3 to 1.

A stock 350 with these heads will be lower, a 383 with flat tops and these heads go well into the 10.5 to 1 range---dont remember the exact number.
 
#7 ·
"what do y'all think my compression ratio would be with flat-top pistons?"
.
If you have a specific piston in mind, the info that comes with the pistons usually tells you the projected compression ratio with different sized combustion chambers. If the data doesn't specify 58CC you can use any one of several compression ratio calculators available here on Hotrodders.com to find out.
They will typically give the comp.ratio for 64cc,76cc etc.
Here's the calculator I use...
http://www.bgsoflex.com/cr.html
 
#8 ·
The L98 Aluminum Corvette 58cc Heads are not so easy to come by these Days . But you still can Find the Iron L98 F-Body 64cc 5.7 TPI Heads . I Paid $100 Bucks for the Set I used . I used them Iron L98s on a Dished Piston 350 with .015" Shim Head Gaskets . It has just over 9.25.1 C/R . With most Flat Top Pistons it will be 9.8.1 C/R . The Silv-O-Lite Flat Tops at Zero Deck will push a 355 Build to 10.4.1 C/R . Here are some Photos of the Corvette L98 Heads . For what you would Most Likely have to Pay for a Set ? best to buy New Budget Performance Heads .






http://hotrodhouse.activeboard.com/
 

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#9 ·
89t-top said:
TANGO said:
I used a Set of them #083 TPI Heads on this 350 Build . They are 64cc Chambers with 1.94"in and 1.50"ex Valves . Pre-Vortec Performance Heads . I would say they are good Street Heads for a 350 350 H.P Build .




Thanks for that info, I might buy a set off an 87 iroc.

will they bolt up to my gen1 350 intake?


that motor sounds mean. :D
After you elongate the 4 Center Holes on the Gen 1 Intake to match the 72-degree angle that the Heads are Tapped at it will bolt Right one . Yes I had to do that with my 350 Build . I used an Early Edelbrock #2101
 
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