608 Water Pump

[Bob R.]

I am looking for a correct 608 water pump for my 63. They are plentyful as they were made over several years and for many different models. After looking around a little it seems there are some differences in what I have seen. I want a 608 with no date on it but where the GM is stamped I have seen several different numbers next to the GM. Is there one that is correct or are there several that are acceptable?

[Joe L.]

Re: 608 Water Pump

I am looking for a correct 608 water pump for my 63. They are plentyful as they were made over several years and for many different models. After looking around a little it seems there are some differences in what I have seen. I want a 608 with no date on it but where the GM is stamped I have seen several different numbers next to the GM. Is there one that is correct or are there several that are acceptable?

Bob-----


The numbers next to the "GM" are foundry pattern numbers. These have no direct relevance to Corvette or model year and, as far as I know, are not judged in any way.

However, you do need a pump that is Saginaw-cast. These will not have reinforcing ribs on the driver side of the pump casting and will not have a "T" casting mark. Pumps with the ribs and the "T" were cast at Tonawanda and were never originally used on Corvette small blocks.

[David L.]

Re: 608 Water Pump

Bob,

I have the following non-dated "Saginaw" 3782608 water pumps somewhere in my garage according to my notes:

GM3, non-orig bolts on rear plate, rebuilt, shaft stamped "885118", 5 11/16" hub mounting
GM12, original bolts on rear plate, no stamping on shaft, 5 9/16" hub mounting

Refer to thread entitled "L-84 Alternator Misalignment" at my post dated Mar. 11, 2011 @ 12:20 AM to see a Chevrolet water pump hub mounting chart. !962-1965 water pumps should be 5 9/16".

As far as I know I still have these 2 water pumps as well as a dozen or more other SBC factory pumps from the 1960's.

Dave