1972 304 V8 Water Pump

The design of the AMC V8 water pump changes for 1973, with a bigger front bearing and a higher deck height.

You can buy the '68-72 water pumps from the AMC specialists:
https://theamcforum.com/forum/6872-v8-correct-new-water-pump-photo_topic98457.html

Galvin's AMC Rambler Parts - 02-1259N (02-1259 for rebuilt units)
American Parts Depot - 920 8001A
Kennedy American - CS307



You will pay a premium price for the right water pump, either rebuilt or new. Current price in March 2022 is about $125 for either. There is no price advantage for buying new or rebuilt, and the rebuilt units carry a significant core charge. Cores are scarce, and some owners must want an actual factory core for their AMC restorations.

If the pump you find costs significantly less, it is certainly the wrong part. The aftermarket sellers (RockAuto, parts stores, etc.) seem to call the '73 and newer part "equivalent" though it looks to me like they always give the height along with the listing. This seems like either a minor deception and/or a CYA effort to prevent returns from dissatisfied customers.

To me, the '73 and later pump looks like a better part, even though it's not strictly compatible with the '68-72 AMC V8s. It's taller - likely by necessity - and has a larger front bearing. I expect this was intended to provide a higher accessory load, either because of frequent failures or because of bigger/heavier accessories. I would guess if you have no AC and the factory alternator, the '68-72 part would last just fine.

If you want to run the later pump, supposedly the '73 pulley set will work on your engine. This was a claim in the AMC Forum for a car, not a Jeep. Seems certain it would be the same for Jeep engines, since they were the same (other than emissions equipment?) as what AMC put in their automobiles of the same year. Possible all you need is the fan pulley.

Looking at the parts book, the fan pulley for a '74 is the same as a '73. I would not be too encouraged by this, as there was a fan pulley in both years for WHDC (with heavy duty cooling) and LHDC (less HDC). Then it seems like the accessory brackets change every year through '75-78, with WHDC and LHDC in every year. Many a slip ...

Certainly you could take everything off the front of a later 304-360-401 engine, install it and use the later type pump. Realize that virtually all Wagoneers got AC, and that changes all the pulleys and belt paths. My advice would be - try it if you can, but don't spend a lot of money on parts that might not work out.

Some in the AMC Forum have claimed you can put the later pump in a press and push down the fan hub to the earlier height. Maybe. Again, I suggest you don't spend a bunch of money without being sure your approach will work.

 

Thanks—great info. I ordered American Parts Depot - 920 8001A, and will report how it goes. $129.
The lady that I talked with at American Parts Depot told me some interesting info. Gates apparently used to make both the pre ‘72 and ‘73+ versions, which they(APD) sold. At a certain point awhile back, they stopped making the pre ‘72, and gates made the ‘73+ version the cross. APD had some complaints and returns, told Gates, etc, but Gates basically said there wasn’t much they were going to do. APD commissioned their own to be made to sell from there for the correct pre ‘72. I believe they had several hundred manufactured. So these are completely new, no reman or core.