Hi, I am replacing the water pump on my car because it was the wrong one for it. I am selling a used 407586 water pump with a date code of 124, the only issue I see is that it has a small chip on the inlet (see picture) - I could clean it up and paint it but I figured someone may want to save some money and buy it as is. This pump was running fine with no issues, I am looking to get $125 plus shipping. Please look at the pictures and let me know if you have questions or need additional pictures.

 

You may have an oddity there
Please post the height and inlet nipple size of this unit


USUALLY the 407536 is a #3 casting
I have seen one with an "O" large ID mark:


Weird: same 6-digit 407536 with differing outlet boss ID [3 vs. O]
Also, strange to see an "O" unit with Long length and Small Nipple [6.1, 1-3/4"]

 

Okay, the length appears to be 6 1/2" and the inlet appears to be just shy of 1 7/8" though there is a tapered edge so it could be 2". What's your thought? I took a look at the numbers again and it seems more like an "8" than a "3"

 

Here are pictures I took - I appreciate anyone's help in determining what year & model this water pump belongs to.

 

Check this...

Brett

 

okay, thanks.

 

Okay, I checked this again according to the picture Paladin31 posted and it seems this pump belongs to the "E" body w/AC as it measured just under 6 1/8" by my tape measure... Did I read the stamping wrong - is there a water pump for the E-Body cars that is close to this number which was also used for the 71 & 72 A-Body cars?

 

One generally measures to the pulley mating surface as shown.
The inlet nipple I would call 1&3/4" or 1.8" for short. Not 2.0 for sure.

I see a gap in the LH side of the "3 or 8" digit, so, three it is, to me. My database I have noted it as sometimes misread as an 8. Or you can consider it sometimes misread as a three, whatever. No, there are no similar casting numbers.

As mentioned, the 407538 = 407586 unit almost always has a "3" large ID where yours has the "O" on the RH outlet boss.

Other castings with the 6.1 x 1.8" dimensions include
4-412265 [exceedingly common]
O-404562
and
O-22526206 Aluminum unit

I find that almost all AC vehicles after oh 1975 or so use this size WP. Almost all V8 Olds, period, after 1975 or so.

Further info on the #4 functionally identical casting:

#4 [6.1 x 1.8] is by far the MOST COMMON Olds WP
NOTE that some versions have the CAST IRON Impeller
AW1120 Airtex, Interchange #251-231, [T&J #41120, 55-21118 ?]
Autoline PN 10-1010 per ebay ad 4/2015, shows cast impeller.

 

Ok, so what vehicle is this pump for so I can adjust my ad and price? My engine is the original block 455 that came with the car - were all the bolt holes for the water pump the same in all big blocks built by Oldsmobile?

 

The 407586 water pump you have, though the 8 looks like a 3, is for all 1971-1972 350 and 455Ci. AC cars. Oldsmobile was very accommodating with interchangeable parts, so pumps of this era will work on all rocket line V8's. As Octania mention, the pump you have with the "O" instead of the usual "3" cast on the outlet, make's it a bit of an anomaly.