I have the same experience with the belt, 62mm sc pulley needed the latemodel21 belt wrap kit (then you can use the OEM belt forever). I also think that you would need fuel mods. I have similar mods to the ones you're installing and have datalogged and show lean (dangerous) at the top of 2nd and 3rd gear pulls above 4500 rpm or so. Rob from needswings can help you out with mechanical fuel needs and euro charged can dial back the tune to keep you from running fat all the time. If you don't install a datalogging system then you should have it dyno tuned after all the mods are in place and drive it like easy until you know whats going on.