What everyone else said and I will add that your friend is a little behind the times anyway, if he thinks 2.02 chevy heads are the end-all. The L31 Vortec heads, with their smaller 1.94/1.50 valves and comparatively tiny little 170cc intake runners, will outflow any production small block Chevy head ever made. It's not the size, it's the shape. These heads on a 383 or 400 small block with a short cam makes a great street motor that will begin making good power just off idle. Fiddling with the DynoSim, I've made well in excess of 400 ft/lbs of torque at 2000 rpm's with this combo.