1964 3839175 water pumps

[Dan H.]

FWIW, have noticed EBAY has several of these '175' water pumps for sale by several vendors. Although the casting number 3839175 is the same, these pumps are the later hybrid casting which is a cross between 326 and 609 pumps, also these have the 3/4 large bypass hole. Probably truck usage. The prices of 3 to 5 hundred dollars for an incorrect pump got my attention. The original '175' pump for 64 is altra rare. Also the EBAY pumps have 'dates' on them which is also incorrect. Just a heads up. Any opinions? Regards,
Dan

[John D.]

Re: 1964 3839175 water pumps

Dan, A nice replacement pump is the Airtex pump. Readily available for under $100.00
AW8981HX

[Joe L.]

Re: 1964 3839175 water pumps

FWIW, have noticed EBAY has several of these '175' water pumps for sale by several vendors. Although the casting number 3839175 is the same, these pumps are the later hybrid casting which is a cross between 326 and 609 pumps, also these have the 3/4 large bypass hole. Probably truck usage. The prices of 3 to 5 hundred dollars for an incorrect pump got my attention. The original '175' pump for 64 is altra rare. Also the EBAY pumps have 'dates' on them which is also incorrect. Just a heads up. Any opinions? Regards,
Dan

Dan-------


The 3839175 casting, which changed in minor ways over time, was used alternately with the 3859326 casting for GM SERVICE waterpumps for many years and LONG after both castings ceased to be used for any PRODUCTION application. In fact, I think that both were still being manufactured well into the late 80's and maybe even into the 90's. These pumps were the only SERVICE pumps available from GM for many years for both external and internal bypass applications for all 1955-68 small blocks and 55-70 Corvette small blocks. I believe that any 3839175 pump seen with a 3/4" NPT bypass fitting started life as a SERVICE waterpump.

[Dan H.]

Re: 1964 3839175 water pumps

Thanks Joe, the early 3839175 pumps were marked 'GM 1 thru 4' I believe with no date. looks like a 609 with a larger bypass area that was rounded in front. The later '175' pumps have the cut off on the bypass area like a 326. Yep, those were service for the earlier pumps etc. 3/4 inch hole in bypass. Real common pump. The early '175' pumps I think were production only and quite rare.
Dan