water pump


Rich D

New Member
Mar 19, 2024
Reaction score
1972 dodge dart 318 original engine. I am replacing water pump. went to 5 stores and all had pump, only difference is the impeller on all 5 is on the opposite of mine. will these pumps work? Thanks for any advice.
Pick your poison. 70 and up should the the aluminum with passenger side exit..

all rock auto pump housings are correct except on my old pump impeller is opposite....
i checked marine, I dont think.I found old paper work on this car and i think this pump was put on in 1994, it was just a hand written note that listed a bunch of parts put on back then.i am stumped and all local mopar guys are to. i think i am going to put pump on that all my local stores have in stock. just added a holley sniper which has hand held computer so i can keep an eye on engine temp.thanks
Are you saying the impellers are visible on one and the flat part of the impeller is visible on the other?
Yup, post photos of your old pump and the new one. There are a couple of different LOOKING impellers, but, they should work the same unless this is some oddball marine or industrial application. Some impellers are just a simple stamped steel one whereas there are some cast iron ones out there too. Also, there are 6 blade and 8 blade impellers depending on whether you're car has A/C or not. In many cases, they only carry the 8 blade version to fit everything. That will usually work, but, not always.....especially if some of the pulleys have been changed and are of a different diameter now than when they had stock pulleys. Originally, the A/C cars used the 6 blade and the non-A/C cars had the 8 blade. I know, this seems backwards, but, the A/C pulleys were smaller in diameter and were spun faster than their non-A/C equivalent which used the 8 blade, but, spun slower with it's larger diameter pulley. This made both systems attain the same water flow. Sometimes if you spin an 8 blade too fast, it will cavitate and foam up the coolant causing an over heat condition. The same over heat condition can happen with turning a 6 blade pump too slow, but at least it won't foam up the coolant. The bottom line is that it's best to match the correct pump/impeller with the proper crank and water pump pulleys.