71 SB Waterpump

[Michael G.]

I have what I beleive to be the original waterpump on my 71 with AC. It has two threaded outlets, the one on top is plugged. I have access to what I'm told is a correct date code rebuilt unit without the upper threaded hole. Is this also a correct unit for my 350, or is the dual threaded outlet unit the only one correct for my car? It's a 12/70 build car.
Always grateful, Mike.

[Alan S.]

Re: 71 SB Waterpump

Hi Michael,
I believe for 71 the original 350 water pump didn't have the boss for the threaded bypass port.
Regards,
Alan

[Terry M.]

Re: 71 SB Waterpump

Correct Alan

[Joe L.]

Re: 71 SB Waterpump

I have what I beleive to be the original waterpump on my 71 with AC. It has two threaded outlets, the one on top is plugged. I have access to what I'm told is a correct date code rebuilt unit without the upper threaded hole. Is this also a correct unit for my 350, or is the dual threaded outlet unit the only one correct for my car? It's a 12/70 build car.
Always grateful, Mike.

Mike----


I agree with Alan and Terry. A 1971 should have a waterpump of GM casting #3991399. This pump has no bypass fitting on the top. It was used only for 1971 and early 1972 Corvette small blocks. It was not used for other Chevrolet applications.

[Michael G.]

Re: 71 SB Waterpump

Thanks Guys,
The engine orange on the pump is almost a perfect match to the rest of my engine which made me think it might be the original. After looking closer I found one of the four fan clutch mounting washers was replaced with new at one time. The replacement I have found is apparently the correct unit. Thanks again guys. MIKE.

[Joe L.]

Re: 71 SB Waterpump

Thanks Guys,
The engine orange on the pump is almost a perfect match to the rest of my engine which made me think it might be the original. After looking closer I found one of the four fan clutch mounting washers was replaced with new at one time. The replacement I have found is apparently the correct unit. Thanks again guys. MIKE.

Mike----


If you check that pump with the bypass fitting on the top I think you'll find that it's GM casting #330813 (assuming it's even a GM casting). That pump was not even being manufactured yet when your car was built. You'll also find that the date code will not work for your car (unless you happen to have a pump cast in late 1980 which might have what's apparently a correct date).