Yeah I'd go back to a stock one if your Jeep is running hot. I put 2 Flowkooler pumps in Jeep 4.0s, and ended up taking them out shortly after. One made a clanking noise (WJ 4.0L) and it turned out the plate riveted to the impeller had come loose (common problem), and the other one was in an XJ 4.0L and it still ran hot when at speed. An old engine builder from the Jeepstrokers.com forum told me they caused "too much" flow for the radiator and to try a stock one. I didn't really believe him, but a stock GMB pump with 3 row radiator cured that Jeep completely.