340 Build Spec's
I'd bet doing the same mods (change the ehads to a set of Magnums) to the 318 and you and your Dad wont be able to tell the difference, and you'll be beating up on 340s and 360s at the track. I have 2 340 cores, and a 318. I'm building the 318 next for my truck, to replace the 360. The 349 idea is a very good one, and fairly cost effective, except for the balancing work.