65 Barracuda Barn Find

I purchased this baby blue 65 Barracuda a few months ago. It belonged to this guys mother who bought it new. She passed away 20+ years ago and he just parked it. It has no dents or rust, None. Interior is in great shape, one mouse nest. I got the brakes fixed pored some gas down the carb and drove it. The old gas smelled like Napalm I'm amazed it ran.
I do have a couple of questions. I'm rebuilding the 273. The #4 main bearing was about to fail so the crank needs to be replaced. Where can I purchase a new crank? Also I replaced the gas tank and sending unit but the gas gauge doesn't work or the temp. The temp gauge has the little wire to the heater burned out. Where can I purchase new ones?
I'm a Chevy guy. I drag race a low 10 sec 67 Nova. I'm not use to not having parts available.