I built a 400 and used 305 heads, drilled steam holes. Motor runs strong, got it in a 83 suburban, turning 15's in 1/4. It has .083 dish pistons with 400 crank and 350 rods, and cam 462/480 lift. Not having any heating problems. I did find out that with the 305 heads I'm running 12.35:1 comp. and around 490 hp. You'll also be running 1.84 intake valves with the 305 heads instead of the 1.72 intakes.
[ June 16, 2002: Message edited by: agb1758 ]</p>