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I'm going to go about replacing the timing chain set up for my 79 Hurst Olds come springtime. While I'm at it I'd like to install a rebuilt (planning on using Arthur Gould Rebuilders) water pump. The one on the car will not be rebuilt at the time of the timing chain job due to logistics. As in, the car is presently in South Carolina and I'm in CT.
I'm looking to get a used suitable replacement but I'm wondering what years I can use, this is a 1979 Olds R motor with air conditioning. As much as I would like to find a used one of that era with the Olds Corporate blue paint, time may dictate that I just get one where I can. Does this motor use the same style water pump going back as far as the early 70's or even after 1968?
My goal is to make it look like it was always on the car. Once I pull the one presently on the car I'll also get that one rebuilt and hold it back as a spare. As much as I would like to get that one re-built and re-installed, the timing chain job is job 1 this time around.
I suggest you go to your local auto parts store and get a water pump for your 79 as it will be the correct length for your application. It won’t be blue as from the factory as water pumps were painted along with the engine before they were dropped into the chassis. The new pump will be bare metal so you would need to paint it if you want it to be blue. A reman pump should be $40 or so plus the core charge since you will be keeping the original.
I suggest you go to your local auto parts store and get a water pump for your 79 as it will be the correct length for your application.
I suggest that when you go to the parts store, bring the old pump to match it up. The one certainty is that you will get the wrong one the first time - most of the catalogs are wrong.
Water pump GM part number callout for your engine is 556283 w/AC and HD cooling. Casting number 412265. Later, the part number changed to 12337519. Another pump with that same casting number had an earlier part number for 71-78 which was 231887.
5.95" tall from block mounting surface to pully mounting surface.
80s model 307 V8 with A/C used the same pump. They only had two versions of the pump for the 80s 307. AC and non-AC. Get the 80s GM or equivalent one for AC and you'll be good.
The pic below is what the original pump should appear as- and note the markings of "4" on the left and casting numbers 412265. It was used on 260, 350R, 403 starting in 1979, and up through 1990 when the new number replaced the old number.
Basically it's the Olds V8 HD water pump with A/C.
Quick method to check a pump if you don't have a ruler/tape handy is to place a dollar bill out next to the pump from mounting surface to pulley mount surface. The dollar bill should line up next to it darn near perfectly. If it's noticeably shorter, it's a non-AC pump most likely.
Picture above is generally what a pump should look like, and EXACTLY how your pump should look if you want to keep it factory fresh, and if you end up going to the parts store, there's really no need to bring your old pump. Know it's just a CH under 6" tall (without the pulley centering nub).
Many Thanks for this, I've got time to seek out a nice core I can get rebuilt, if I don't find one I'll use your method to make sure I have the right one ready when the time comes. As much as I'd like to get the one on the car rebuilt I'll only have one shot at this job since the car is not with me locally, and I want to bring the H/O to the Nats next July/Aug
