What water pump is this?
Thread Starter
jobberone
Joined: Aug 2003
Posts: 2,062
Likes: 8
From: Kailua Kona HI
Hate to answer my own question but maybe this helps someone else
Just got private email from a friend who rebuilds these for those looking for numbers and factory correct pumps and alts. Here is his answer to my question:
That waterpump is for any small block that does not require the upper bypass from the intake, usually a cast iron intake. Your 65 Hi Horse with aluminum intake would require a 3859326 waterpump with an outlet on top as well as one on the side to be "CORRECT". Of coarse any short small block water pump will function ok. I have had some luck finding these at the local Auto Parts Store by asking what they had in stock for the application and sometimes they have a rebuilt GM casting with the correct casting #. But usually they have a RePo casting which is useless to us number guys. The older the store with old stock the better the chance. Then there is eBay which I see them quite often. I just remembered that the early ones to about mid 1967 were 1/2" NPT at both locations, after that the top outlet was 3/4" NPT and the side outlet to heater remained 1/2" NPT. The 1/2" ones are rare and will bring a good price, about two to three times the price of the 3/4".
That waterpump is for any small block that does not require the upper bypass from the intake, usually a cast iron intake. Your 65 Hi Horse with aluminum intake would require a 3859326 waterpump with an outlet on top as well as one on the side to be "CORRECT". Of coarse any short small block water pump will function ok. I have had some luck finding these at the local Auto Parts Store by asking what they had in stock for the application and sometimes they have a rebuilt GM casting with the correct casting #. But usually they have a RePo casting which is useless to us number guys. The older the store with old stock the better the chance. Then there is eBay which I see them quite often. I just remembered that the early ones to about mid 1967 were 1/2" NPT at both locations, after that the top outlet was 3/4" NPT and the side outlet to heater remained 1/2" NPT. The 1/2" ones are rare and will bring a good price, about two to three times the price of the 3/4".
