1990 TPI iron 305 heads vs L98/ZZ4 aluminums
#1
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Join Date: Sep 2003
Location: Richmond, TX
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Car: 90 Formula hardtop
Engine: 5.0 TPI
Transmission: T5
1990 TPI iron 305 heads vs L98/ZZ4 aluminums
OK I don't want to go through the trouble and expense of pulling heads to swap out for something that does exactly the same thing.
CC - same? 58cc?
intake port volume - same? 163cc?
exhaust port volume - same?
chamber shape same?
valve sizes Intake - 1.94 vs 1.84? Exhaust valve same? 1.50?
chamber shape same?
CC - same? 58cc?
intake port volume - same? 163cc?
exhaust port volume - same?
chamber shape same?
valve sizes Intake - 1.94 vs 1.84? Exhaust valve same? 1.50?
chamber shape same?
#3
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Car: 90 Formula hardtop
Engine: 5.0 TPI
Transmission: T5
So other than intake valve size and weight, they're identical?
port shape? combustion chamber shape?
If that's it, it ain't worth swapping out heads.
#4
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The aluminum heads also don't have an exhaust crossover so your EGR system won't work AND the aluminum heads use the earlier style intake bolt pattern.
I have heard several people report that the ZZ4 versions of those heads have significant port/valve/valve seat improvements over the original assembly line corvette L-98 heads.
I have heard several people report that the ZZ4 versions of those heads have significant port/valve/valve seat improvements over the original assembly line corvette L-98 heads.
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