I have a vey similar build to what you are thinking about, it is a NAPA style rebuilt 72 360 .030 over bore with stock type very low compression pistons. I stuck in a comp XE268 I had lying around, mopar .028 head gaskets did a light port job on the heads, stuck an M1 single plane on it and I already had TTI headers on the car then I stuck a 750 carter competition AFB on it and it is very quick even with my 2.76 gears. I think a better cam with the low compression would have no more intake duration and little less ex duration, I think a comp 270 magnum would be perfect. I am useing the GM 3100 V6 springs, if you do that check VERY carefully to make sure you are not in coil bind, the 270 magnum has a slightly shorter ex lift so you should be fine but check anyhow. Even with the 2.76 gears and 225-50-17 tires I found out mine will pull to 6000 rpm even in high gear with enough road