Does anyone what the specs are for the stock 89 L98 heads? And whats the most HP you can get and still use the stock heads?

 

Valves:
1.94 intake
1.5 exhaust

Combustion Chamber:
58cc (Aluminum Vette Heads)
64cc (Iron Camaro, 'Bird, TA heads)

Flow #'s (int/exhaust) - These are the 58cc Vette Numbers, they should be very close in the ballpark, if not the exact same.

0.1" lift 55/52
0.2" lift 120/104
0.3" lift 160/133
0.4" lift 186/151
0.5" lift 196/170


Not sure on the runner volumes, but its probably not that impressive.

Trickflow had a match against Vette L98 heads and flowed 40hp better. At the time, the L98 was making 420hp. So I guess you could get that high, but it would be tough, and you'd have alot of porting to do. Honestly, I would just get new heads. Trickflow's 23 degree aluminum heads are $1145.95, which is a pretty good deal.

 

163cc intake runner.

 

http://purplesagetradingpost.com/sum...fo/heads1.html

http://chevyhiperformance.com/techarticles/41598/