i've got a 98 gsr and i just got an unorthodox street under drive pulley and two aem pulleys (power steering/alternator). Can anyone tell me what belt sizes to use with this combo?

 

u should have gotten belts with the pulleys... at least i did with my aem pulley

 

the belts did come with my aem pulleys, but they are the right sizes for the stock crank pulley, now i have a smaller UR crank pulley, so the belts are useless.

 

well, i didnt know that the UR pulley was smaller... i would never put on a lighter crank pulley... but i would assume that u can find out the belt size if u know the difference in size from pulley to pulley and do some simple math

 

why wouldn't you get a lighter crank pulley?