273 4 barrel intake manifold, early 64-65 with 5/16 bolts

Just remember, that motor was made for a 2 barrel, unless you put a different exhaust and maybe cam it isnt going to run better with a large 4 barrel on it. Just don't go crazy on the carb
I appreciate that and yes you’re right, the plan is for a isky e4 or a racer brown cam and the exhaust will be adjusted accordingly. Will there be any issues with the transmission? Shifting? Rear end?
I’m not looking to hot rod whatsoever and I’ve got a great mentor walking me through this who has experience in the exact matter.