I would rebuild it and keep it a 350. 2000 dollar budget isn't big enough for a stroker. Put some GM Vortec heads on and a nice street cam. You seem to have the carb and manifold covered with a aftermarket so that is no problem. Good ignition system already so your good on that.
Tech if he has a 72 and it's never been changed then I wouldn't doubt most likely he has freeway gears like 2.73's. Then again it could be anything but that is what I noticed in a lot of 73's and 84's and my 85 has them as well.