As woody mentioned. I was told years ago when i made the switch to alcohol to back the timing off to keep the motor from detonating and knocking the rod bearings out of it. I get 4 seasons out of my motors and when i take them apart the rod bearings look like new. Will it go faster with more timing? Maybe. But reliability is more important to me and consistency. Shoe polish takes care of the rest

Two things,Is the combustion chamnber the same SIZE on both heads, and what intake manifold ?Manifold could have been a restriction on original heads and likewise on AFR210s.Bill C.

quote:

Originally posted by mavman:
Weighs 2700 race ready to my knowledge. That's close. I haven't personally weighed it. PG 1.76 and best I can tell, stalls about 5600. Takes the stripe at around 6900-7000.

Needs more stall rpm imho. 6100 – 6200 would be an improvement. Makes more hp at this stall rpm.

I agree with Bill. The intake is probably the choke point on this combination. With the GM heads the intake probably did not pose a restriction in airflow, now with better flowing heads the intake is not allowing the airflow needed for them.

I flowed a set of heads a long time ago with and without an intake. A stock out of the box intake killed the airflow. A well-ported intake actually increased airflow above .600 lift, I was not expecting to see that.