1970 gto 455 water pumpp part number
 

Hi everyone, I tried searching but came up with conflicting info. Does anyone know the original gm part number for a 1970 gto 455 water pump? Thanks in adavance.

This is the part # : 478126 (from bulletin on using 70 pump for late 69 Bird)
Not sure if it is the same cast #?

Well....
Found this for a 1970 Bird: 9799124
But they may be different.

:)

yup thats what is throwing me off. if it helps my build for my 70 gto was october of 69

I think the 70 pumps are the same size. (from fan pad to mounting surface)
69 had different sizes I believe?


:confused:

Should be 9799124 for all V8's.

Dennis

From the factory assembly line, ALL '69 model Pontiac V8's received the 4" hub height "351" casting 11 bolt waterpump. I've pulled these for near 40 years as specialty cores.

In July of '69, Pontiac Central Casting began pouring the first "124" (9799124) casting 4 1/2" hub height waterpumps for the upcoming 1970 model Pontiac V8's.

NOTE: the "124"s were NEVER installed on production '69 Pontiac V8's.

The '69 1/2 BS origin...
In the late Fall of '69, the '70 model "124" casting waterpumps were introduced as a SERVICE REPLACEMENT for ALL '69 Pontiac V8's in the A, B, & GP product lines.
This dealership service procedure noted in Pontiac Service bulletins required changing the 1969 water pump pulley to a correct 1970 Pontiac V8 application pulley when the taller pump was installed.

This service replacement procedure was NOT encouraged for '69 Firebird usage, with the main reason being 4 core radiator equipped Birds with the 5 blade flex fans & their very short fan spacer
did not have as much room. it got quite tight up front. Positioning the fan another 1/2" forward was out of question. Thus late season '69 V8 Birds continued to be built with the 4" hub height "351" casting
water pumps til the end of Firebird production in November of '69.

Of note, the "124" casting "70 model waterpumps continued to be cast up into June of 1970. Several have even been documented as being originally installed on very early built '71 models.

In early July of '70, the "138" casting 11 bolt waterpumps began to be cast & assembled & the "138" pumps were cast up into mid '72 model production.