Water pump

[maddog]

So I discovered that someone put a 2.5L water pump on the 4.0 I got from the junkyard (it was on there when I got it from the yard and this is the engine I'm building as a stroker). The pump is brand new so I was wondering if it would be safe to run said water pump on the engine or should I get the 4.0 water pump?

[Taylor]

My guess would be no. But if they are actually the same part number it might be ok.
I think if I had the same problem I would replace it with the 4.0L and maybe get a high Flo unit.

[maddog]

Yeah that's kind of what I was thinking of doing but figured I'd get y'all's input first. And they are two different part numbers even though I do know they both spin in the same direction but the 2.5 one uses a smaller pulley than the one for the 4.0 does.

[maddog]

So after replacing the 4-cylinder water pump with one for a Cherokee 4.0. I was at the junkyard and happened to look into the engine compartment of an early Grand Cherokee with a 4.0 and it had the same water pump as the 4 cylinder, just with a different pulley, so it looks like you can actually use a 4-cylinder water pump. You just got to make sure to get the pulley from an early 4.0 equipped Grand Cherokee to make it work.