water pump issue

Can someone tell me when a short water pump is used and when to use a long water pump on a small block chevy? does the harmonic balancer have a roll in this matter?.........thanks for the help

I think it is a year thing. I originally bought a long water pump for my 350 because it is a 99 engine, but it was too long to clear my electric fan. So I ordered an earlier water pump setup and it is the short one. I don't have my Summit catalog here to get the exact years for you, but the short ones were used like in the 70's, I think, then the long ones came on the scene.

Someone else might be able to give you more definitive info.

Don

I would say 1969 was when the long water pumps were on most of the Chevy cars . But the corvette and some truck still had the short pumps .

The short pump was stock on the early engines, a lot of street roders use the short pump because of space restrictions in the engine bay, pump has nothing to do with the harmonic balancer.

Thanks for some input, But I'm wondering if its because of the different diamenter harmonic balancers and pump pulley's clearance. I have a 350 chevy with the larger balancer on it.....chevy makes several different spacers to space the fan out to the radiator, so I was wondering, why the different pump lengths. I'm getting ready to buy an aluminum water pump and want to research this before paying for a bunch of shipping charges....can anyone help me with this?.......thanks

I switched to a long pump because I had the room and I wanted to use the accessory holes in the head to mount the alternator. This way I could use a shorter alternator belt. It is much more compact. What about mounting the fan in front of the radiator as using it as a pusher fan?