you can use the pulley with either crank. a lot of people seem to think it is a bad idea. honestly i think it is not the best idea but i am using the 4 weight crank with UR pulley myself and i have seen others do it too with no real problems. upon inspection of main bearings they showed more damage from vibration than an eight weight crank but it still ran fine. unless you are racing or have a mad destiny to have all the HP you can get. i would say use an 8 weight so the crank itself is balanced well then get an aluminum flywheel and remove some material from the outer most regions. this is worth the same if not more savings in inertia than what you would gain with a 4 weight crank and you keep a balanced crank. i am designing a large displacement crank for my engine and balance is extremely important especialy at high revs. if rev high and race hard and you dont mind replaceing mains every couple months its a great idea.
If you have the standard 4 counterweight crank in the SR20VE w/ the stock pulley, are there any worries of bearings going bad during the occasional track day every few months? Or is it only if you have that with the UR pulley? So far mine only has seen up to 7500rpms, as i still have the stock cams and I still usually short shift on the street a bit, even if i push it.