The pulleys have no bearings attached, if something is screwed up it's not related to underdrive pulleys.
With that said, concentrate on doing one engine and doing it right.
So many people come here with these pipe dreams about bigger and better later, probably less than 5% ever get to that point, And when they do it's miles apart from using basic 302 parts.
A dart based engine with quality parts is a 10k project by itself, then you need a car that will support that much power without killing you or destroying itself (trans, brakes, rear,
suspension).
So, if you don't have 15-20 thousand dollars sitting around waiting to be spent on your car, just build a good 306 based setup while concentrating on getting the whole car right.
If you really want to use the same heads in the future, buy twisted wedges and when you get your 363 have TEA cnc them.
And removing the back seat is not only pointless, but looks horrible.