PS pump compatibility

[Mektek]

I thought the Power steering pump for the 4.2 are the same for all models.
I see a listing that has a pump specific for the EXT models and v8s.
Are there physically different pumps for the long wheelbase versions?

 

[Mooseman]

We've never been able to really determine what the difference is. The EXT has a different rack and pinion and also calls for a different belt for a different pulley size. That pump may have a different pressure setting internally. Externally, for the SWB and SWB, they look the same.

I'd just stick to the one listed for your truck.

 

[Mektek]

So any pump would fit, but there is something different about the EXT. Although I'm curious what would happen, I'll go with the SWB model. Somewhere I've heard that the SWB has variable ratio and the EXT doesn't.

 

[Mooseman]

There are different ratios:
Rack and Pinion ratios by model

 

[Mektek]

So the EXT has a quicker ratio to make up for the larger turning circle. But I wonder what the exact difference in the pump is. Probably higher pressure.......