I think the impeller slots themselves are a different width so it moves a different amount of water.
I thank everyone here for all the help and information they provided.
Now I'm just trying to decid which route to go with all this information.
I called PoolSupplyWorld again to verify the fit of the two motors listed above (B2975 and EB2975), and the guy suggested I call Hayward first to verify all the parts I need.
So once I reached Hayward, they told me I just need to replace the motor and the impeller. My diffuser is rated for 1/2-2HP motors, so no change is needed there.
The part numbers they gave were:
Hayward SPX1607Z2MS The rep said this was their energy efficiant model.
Impeller SPX2607C
So it seems I now have a third motor in the mix, but I'm having trouble finding any information about it other than this; Motor, 1 H.P., Threaded Shaft, 2-Speed (Single Phase, 60 Cycle 230V)
*Update*
I found the motor listed on Amazon, and if the label is correct it reads; 1 HP / 1 SF / 3450/1725 RPM / 6.8/2.6 Amps / 56J FR.
So it seems this motor is slightly less efficiant than the other two, but how much does that translate to $$?
Yeah PSW gave me that kit.
http://goo.gl/NiZOl5
I have to check, but I think I already have that from when I was going to replace my seals last year due to the leak that cause this whole mess.
So I should stick with the Century B2975 or Emerson EB2975 for better low end efficiency? That was my first guess when I saw those numbers on the Hayward.
And everything with this should mount as long as I order the 56J Frame, and a 1 HP impeller?
Keep in mind that a 56J motor comes in two diameters and the Hayward direct replacement motor is a smaller diameter than the other two motors that you are considering. This means you will need to modify the motor support although I think the SuperPump has a removable motor support but you may want to double check before pulling the trigger.