I'm looking for a part number for a belt for a 440 for taking to the dyno with no other accessories. I have stock pulleys for a non ac car. Double pulley on the crank and the single for the waterpump. I just wanna run the waterpump off the crank during the dyno I've seen people with pictures of the belt on their engine and figured someone out there know the part number instead of just mocking it up and measuring then sorting out belts at the auto store lol.

Any help? Thanks

For anyone needing a belt for this purpose with just two stock pulleys on a big block or my future reference a masterpro (from O'Reilly's) 7330 fits great.

Mopar has used several different combinations and sizes of pulleys on BB non air conditioning motors since the early 1960s, which year are you needing the info on?
You can use a 3/8 inch size rope around the pulleys to get the outside length in inches and then try that length belt on your motor, They don't need to be really tight to spin the water pump, a little loose works fine
I use one of the old Mr. Gasket, Moroso 12v electric water pump drives for all my dyno testing, cheap and fool proof, if it is turning the belt the water pump is moving water