I did learn, the 400/512 intake seems a bit more restrictive than the 440 based intake. I gained a bunch of ET when I ported the intake. So, it might be a plenum thing. We have debated this around the shop for a while as the small journal and light weight B combo should be faster than the RB, but it has not turned out that way for us. Same carb, same heads, same cam, same headers, same car.

Dragula .....what cam, compression were use with the 400/512 combo i thought i read somewhere that you were useing -1's for heads ?