no idea where the timing is.

I agree with above. Adjust the timing for max rpm or max vacuum, preferably with the tranny in drive (insure parking brake works, chock wheels, etc). My engines usually idle OK from ~20 deg BTDC to 5 ATDC. If it runs faster at far advance ~30 deg BTDC, I think a sign that your idle mixture is lean. Advancing more is usually good, except if it causes pinging at WOT. That is why new cars have knock detectors and the controller responds to that. If it runs OK in neutral, even wanting to rev up with a little advance, but dies when you put in it drive, I think that is also a sign of too lean. Your cam is more aggressive than the factory one, meaning better for high rpm racing, so the engine will never idle as well as original. Some people prefer that blub-blub sound. Rhoads variable lifters are one cure.

A timing light will only help if the timing mark on your damper is correct. The outer shell sometimes slips when the rubber gets old. However, whenever I suspected mine wasn't right (because engine wanted a lot of advance) and I checked the marks against a dial indicator on the piston (w/ heads off), the mark was perfect. I think the carb was too lean, which was a constant problem with my 225's Holley 1920. There are many surplus timing lights and dwell meters, since not useable on most cars since ~1990. Check ebay or craigslist. I found both in a rolling tool box my wife got at the thrift store.