Okay, Im readying a motor swap on my Trans Am. Im swapping the LG4 with a 71 350/270 horse. Motor has 8.5:1 compression (flat top pistons, but apparently that doesnt make any sense) and is pre smog. Which motor would have better heads on it? I am planning on having the ported and polished, but wondered which should I have done. Motor is getting a cam (.460 lift range/ 220 duration range) an intake manifold, and full exhaust system (headers whole 9 yards.). But what heads would be better to take to the machine shop. Thanks in advance guys.