well, i was thinking about dropping my 454 into it, but i got talking with a few people, and they said drop a 350 LS1 because the 454 top end isnt that good. the 350, got lots of HP and a decent top end. the 454 only got HP well what else are you planing to put into it?
the 350 wouldnt be to bad but personally i would go with the 454, unless you plan to race it, why not have a louder bigger engine, thats just my opinion, im working in a techshop for autobody and the older guys in there just restored a 67' Mustang GT500 and put a 454 into it, it sounds so awesome, l love cars