Sorry for bringing up a 2 month old post but saw this and wanted to jump in here and post some experience with different pumps, incase you still havent bought one or for someone else that is looking for one.
To start out with I pieced a system together with a combine orbital and a tractor type 8"x2" ram and a stock style saginaw pump, had continuous problems getting hot not turning and so forth. I junked the entire system. (looking back a lot of the problem may have been in the combine orbital..dunno)
Then I went to 2 single rams and a cast iron KRC pump with a new orbital. At the same time my buddy put the same exact thing on his jeep.
I am running a ford EFI 351 and was running half tons with 5:13's on 38" boggers
My buddy was running a 4.0 H.O. with the same tires and axles.
Both of our cast iron pumps tore up about the same time, less the a year. The supplier hooked us up with aluminum pumps and they did good on mine for about a year and half, then I changed the entire rig.
My buddy still has the KRC aluminum pump on his Jeep. He has since changed to Rockwells with 44"s and still the 4.0 H.0.
I changed to two steering rockwells with 44"s and went with POS 4wheel steer system.
10" stroke rams and the P style pump, new orbital and rear steer box..ect.ect.
After about a year and half the P style pump started whining a lot, during that I was building another rig for a guy and ordered POS stuff but his is the new "Dry" style pump and I liked that so I ordered one for mine too. So I am in the process of putting that on mine this winter, so I never did figure out what was making my old pump whine so much, dont know if its shot or not.
Overall I did not like the KRC pump, I personally thing the POS pump is twice the pump as the KRC, my buddy with the jeep is considering changing his KRC to the POS pump soon.