[Mister Pontiac]

Phoenix, I can understand your hesitation with budget constraints, but as far as your skills? If you have successfully built a SBC, you can certainly build a Pontiac. Sure, they're different, but they're actually extremely straight forward with a ton of interchangeable parts (as mentioned).

Another thought...

I love to find a 'good used' engine when possible. Someone will have a good running 400 they pulled to drop in a 455, or perhaps a wrecked car with a good running engine. If you can find one of those, I think you'll come in well under your stated budget. I've done this very thing for years when I need a 'place holder' and just want to drive the car.

You're well on your way with the brakes done and original engine/trans pulled. Finish up the fuel system rebuild, meanwhile, see if you can't find a good running 400 or the like for half the price of your estimated rebuild cost. Cleanup the Muncie, drop it back in, and go spin the rear tires! It's one of the fastest, most cost effective ways to get your car back on the road where it's always more fun.

To quote Frieberger from Roadkill, "Don't get it right, just get it running!"

There will be plenty of time to rebuild that 350 later as funds become available, but you'll be thousands of miles and smiles down the road by then.