[unruhjonny]

So I finally figured this out, it's only the casting date which has me perplexed.

I recently bought a water pump based on three factors:
1) purported to be in good shape, and from a 1971 model year engine
2) 979- part number (I knew that this was a 1970 prefix, and not used for 1971)
3) a clearly visable May 1970 casting date in the listing.

When I received it in hand I was confused because the end of the part number was wrong, yet the casting date clearly put it in the 1970 model year;
I verified that it had the same timing housing bolt pattern (I cannot recall precisely when that changed, but knew that was a variable).

I just did another search, and finally got it;
This is a "1969" water pump which happens to be 1/2" shorter than a water pump which would be correct for my car.

Does anyone know how long that these 1969-'351 water pumps were being cast?

This one having a E070 (May 7, 1970) casting date has really thrown me - Especially since I have read here of 1970 service procedures which called for the "1969" pump being replaced with a "1970" pump - and the pullies ect being changed out to accommodate the longer pump.

[Bird_collector]

If this is for your 70 Formula, the correct water pump for the 70 engine would be 9799124.

As I recall, that service bulletin mentioned using the new style pump on several 69 models, but I don't think the Firebird was one mentioned (at least initially). This makes me believe that the 351 water pump may have still been utilized for at least the Firebird.


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[Bird_collector]

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[Bird_collector]

I reviewed my notes on this:

11/1/1969 Parts catalog (before service bulletin released) lists:
#9797581 69 All V/8
#478126 70 All V/8


7/1/1971 Parts catalog lists:
#9797581 69 F/8
however,
#9790522 69 P/8-T/8-GP/8 casting# (9)799124 *3 - footnote
(*3 when replacing OEM pump #9796351, fan pulley #9799127 must also be used)
#478126 70 All V/8


11/1979 Parts catalog lists:
69 F/8 #9797581

Notice that the part# for the 69 Firebird does not change in 10 years. Also the part# is for the entire assembly and is not the same casting number found on the exterior of the part.

Can you post pics of the casting number and date please.


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['ol Pinion head]

Love to see a closeup of that casting date.

Have never personally seen an original "351" casting water pump cast after mid July of '69. Have been pulling "351" casting pumps since the early 90's, have had multiple dozen & have discarded or passed up many more ( have to pull them & examine the machined flanges to see if badly rust pocked). Have also owned several NOS "351" water pumps that were cast in June & July of '69.

The first production Pontiac V8 4.5" tall water pumps were the "124"s cast in July of '69. These first "124" pumps were cast and installed on engines destined for '70 A, B, GP's, & later on, '70 1/2 Birds. From examining and pulling original pumps & pulleys from late season '69 Birds, they still received a "351" pump.

[unruhjonny]

Sure thing!
(I can only attach one image at a time because I am uploading from my iphone)

[unruhjonny]

and one more:

['ol Pinion head]

Jon, that's a first. Pontiac must have figured out that some '69 Firebirds were going to need replacement pumps. The procedure to replace the "351" wp with the taller "124" pump on occasion created a fan clearance issue.

[unruhjonny]

Originally Posted by 'ol Pinion head

Jon, that's a first. ...

And I think therein is why I was stummped;
I figured that everything pointed to this being a good "1970" water pump!
lol

Weel, a 1/2" spacer (and longer bolts) will make it a good water pump

[Bird_collector]

Very cool find. That's a real deal service replacement there. Do you happen to know if it was removed from a 69 Firebird engine by any chance?


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[unruhjonny]

the guy I bought it from said it came off a 1971 400.

[grivera]

My 69 Firebird was built in Feb 1970 and has the short pump.

[unruhjonny]

Are you sure you're not mistaken?
If my memory serves me, I thought the last of the extended 1969 model year F-bodies were built in December 1969 or very early January 1970;
I had understood that production 1970 F-bodies were started in late January for the February launch.

[grivera]

That's what I recall based on PHS doc's as there were no 1970 Birds. That being said I'll double check and post pic of doc's.

[FASTASSBIRD]

I got one also. Same date. Missing a digit in the casting number. Cool piece taking you shelf space

[unruhjonny]

my knee-jerk thought was something akin to this, but really, since this one is only 1/4" shorter, then all you need is a shim and longer bolts and it could be used in place of the "regular" longer water pump.

['ol Pinion head]

One half inch is not a shim, it's a spacer. Doing so would be very hard on the cartridge bearing & seal, I would never shim a water pump pulley out more than aprox .060" & that would be if i was forced (with a gun to my head) to use some aftermarket shiny alum junk. Bottom line, one shouldn't ever have to use a shim in that location if brackets & pulleys are correct.

[unruhjonny]

ok, fair enough.

I had just figured that since I have seen a myriad of different fan pulley spacers, that another 1/2" (mistyped 1/4" earlier) wouldn't be a big deal.

I cannot recall off hand the length of the 1970+ Firebird fan spacer, but see these in varying lengths from just over an inch, to something like three inches.

[grivera]

Originally Posted by unruhjonny

Are you sure you're not mistaken?
If my memory serves me, I thought the last of the extended 1969 model year F-bodies were built in December 1969 or very early January 1970;
I had understood that production 1970 F-bodies were started in late January for the February launch.

So I mixed build date with ship date (2/10/70). Here’s a pic of my sheet - where does one find build date?

[unruhjonny]

The build date should be on your cowl tag.

That looks like a zone car, not a dealer order car;
It was probably shipped to a zone lot, then invoiced when it was shipped to a dealer.