72 350 Crank Pulley Diameter?

[69l46vert]

I'm hoping to learn what crank pulley is the right one for this 1972 GMC K2500 4wd 350 cu. in. No AC pickup. I have the power steering pulley but the crank pulley is missing.

Does anyone know the diameter, or even better, the part number? Or just something that will work?

I believe it to be a single groove pulley that is very close to the harmonic balancer but don't know the diameter. I'd like to keep the stock length belt.


Also I maybe should mention that it's the short water pump, Alternator and PS pump are on the driver's side. The existing water pump pulley is single groove.

Any help very much appreciated, Thanks!