Quote Originally Posted by Fast355 View Post
The added compression of the aluminum heads more than make up for the slightly less flow.
That being said the F/Y-car timing tables are not a good bet for 1,000+ lbs more car. The car will always be under more load and detonation will be likely with all the timing.
He would be better adding small incremental amounts to the B-car tables. The F/Y car VE tables should be a better starting point though.
OE IronHead LT1 is 10.5to1 compression.
If he uses the gasket that goes with the iron heads, but with the aluminum heads instead, what will his compression be?
I'm not a lawyer, I'm genuinely asking.

That said, the B-car tables were written for 87 octane, whereas the F- & Y-car tables were written for 91 octane.
So if he uses F-car spark tables, he should definitely use 91 octane.
PLEASE feel free to correct me if I'm wrong about any of this.