88 GMC 383 Stroker

I've got a 88 GMC Sierra with a chevy 383 stroker. It's a 1972 block. It has a mechanical water pump. I want to order a March performance pulley kit for it and I need to find out if I have the short or long pump. How can I tell? I've got the casting number but that hasn't done much for me so far. Anybody out there know? Thanks. Also, how can I tell if I have a pressfit or keyway power steering pulley?

TurboGibbs

iTrader: (6)

If there is around 1/4"-1/2" gap between the water pump and the timing cover you have a short one and if it is 1" or more you have the long pump.