'71 Duster 440 or 360? Pros and cons
Theres no replacement for displacement! Seriously, ANY big block car is going to be a blast! I'm from Oz, and am currently building a 400/470 stroker big block for a VF Valiant hardtop (I think 68/68Dart coupe in the U.S?). We are in the same boat in that this will be my first big block car. Of course, there will be weight differences etc etc, but are easily overcome with aftermarket bits (ally heads and manifolds for example).
I was going down the path of a 360/408 stroker, but every man and his dog seems to run them, and I like the idea of not needing to rev the nuts off my BB to make power. IMO, less revs means less strain on you motor, and I'm not really in a position to be under the bonnet after every run.
Most of all, its nice to be able to pull up at a club meet, or car show, and know that I've got something a bit different to most of the other guys. I'm not a racer, I'll run it once just for a timeslip, but mostly it will be a weekend warrior with enough stick in it to embarrass a few small block Chevs and Fords we have in our area! It really comes down to preference; Either build will impress you if you do it right, but if I already had a stout small block equipped car in the shed, I know what I'd be building!