350 water pump question

treys3502 · #1 March 31st, 2018, 06:57 PM

Hello, I recently found a neat 69 Pontiac Tempest i was looking at buying, car ran, but only problem was the water pump. The owner replaced the water pump with a unit he got from O'riellys, well it sits about 1/2-1inch further out than the original, and as a result the belts don't line up. Its an original AC car but the ac has been removed, and its the original 350 to the car. My question is are 350 and 400 water pumps the same and are there 2 different pumps? Where can I find one that will work as it seems the local parts stores will be no help. The owner kept the original water pump to reference after he saw the new one didn't fit, he didn't give a reason for replacing it. Thanks in advance!

***melsg5*** · #2 March 31st, 2018, 08:46 PM

there are two water pumps in 69, early and late. Your description of the problem, 1/2' difference, is the exact difference between the two pumps. You need the early pump, measures 4" from the back of the pump to the mounting surface of the hub, versus the late pump, 4 1/2" for the same measurement.

treys3502 · #3 March 31st, 2018, 08:53 PM

Ok so im assuming auto parts stores like O'riellys just carry the later pump, could I just ask for one from a 68 350, assuming that is the same as a early 69 pump? Also I know the blocks are very similar, are the pumps the same between a 350 and 400? places like summit only seem to carry 400 water pumps.

treys3502 · #4 March 31st, 2018, 09:36 PM

Ok so ive done some research and it appears that the 4inch water pump is now essentially obsolete with no one making them anymore and rebuilding it costing hundreds of dollars... is there a pulley I can put on this new 4.5inch water pump that is backset half an inch and will realign everything?

janerik80 · #5 April 1st, 2018, 05:21 AM

Ames seems to have a water pump that is referred to as "early 69 water pump, short hub" Could this be what you're looking for? Part number N140NW

***melsg5*** · #6 April 1st, 2018, 11:03 AM

As stated above www.amesperf.com has the correct pump and NAPA has the pump also WP58302.

cammerjeff · #7 April 2nd, 2018, 07:56 PM

And you cant use the 68 water pump as it has a different bolt pattern. When changing the water pump I would at least also change the transfer sleeve seals, if not the sleeves and divider plate also.