March and Billet Specialties make a complete serpentine belt kit but they are pricey. I think Vintage air has a set up but probably not sold other than with their a/c kit. Summit and Speedway would be less pricey if available but the least expensive would be a factory set up off a 350 in a pickup or suburban in the junkyard. All these are for the long water pump so if you don't have room the aftermarket ones can be bought for both the long and short pump. If pulling one from the yard be sure to get every last bracket, bolt and nut and a few pictures won't hurt. They use a reverse rotation w/p so get it also.
