Chevy SB water pump ID help please

[Keith B.]

73480248629__41312BD2-50FC-4068-969B-33CA7035F2D4.jpg73480251466__06D1414D-3869-4659-9A53-C4B2DD0BB3F2.jpg

I get the date is February 22 of I am guessing 1972. But is this an assembly line pump or a service pump. Thanks

[Gary B.]

Re: Chevy SB water pump ID help please

Keith,

Part number is probably 3859326 if that helps.

Gary

[Joe L.]

Re: Chevy SB water pump ID help please

[ATTACH=CONFIG]121759[/ATTACH][ATTACH=CONFIG]121768[/ATTACH]

I get the date is February 22 of I am guessing 1972. But is this an assembly line pump or a service pump. Thanks

Keith------


Very common small block, short-leg, external by-bass, waterpump used in PRODUCTION from 1964-68 on Corvettes requiring external bypass type pumps. Early examples have the top bypass tapped for 1/2" NPT and later are tapped for 3/4" NPT. This pump was also once widely used for GM SERVICE for all Chevrolet short leg applications after the internal bypass pumps were discontinued. It was then supplied with a plug to be installed for internal bypass applications. However, to my knowledge, it was never supplied with an adapter to convert the 3/4" NPT by-pass fitting to 1/2" for the very early applications originally using the 1/2" NPT fitting.

[Keith B.]

Re: Chevy SB water pump ID help please

Joe it does have a capped bypass plug up top
73480252948__BDB01CF3-E562-4CCF-9073-A37EEF05878E.jpg

so what your saying is it's a service pump made for all SB

[Joe L.]

Re: Chevy SB water pump ID help please

Joe it does have a capped bypass plug up top
[ATTACH=CONFIG]121781[/ATTACH]

so what your saying is it's a service pump made for all SB

Keith------


Given the 1972, 1982 or 1992 casting date, I would say it started life as a SERVICE waterpump. Short leg, external bypass waterpumps were not used in PRODUCTION after 1970 except for 1972-82 Corvette and some trucks which used a different short leg waterpump not to be confused with the earlier 3859326. These Corvette waterpumps, GM casting #330813, had a plug installed in the upper bypass fitting in PRODUCTION.

[Keith B.]

Re: Chevy SB water pump ID help please

Thanks for the help