Her guys, looking at a 4" lift for my 91 cummins 4WD. This is the one I am looking at...

http://www.roughcountry.com/dodge_4wd_70-93_pickup.html

Says that it will not fit the diesel models. Does anyone know why? I assume that it would only be because the front springs prolly arn't as heavy duty as the diesel springs. Or is there more than that?? Thanks for the help guys!! Paul

 

If it says gas only then the springs aren't made to carry the weight of the cummins they al sag.

 

The cummins will make even diesel rated springs sag a little.....don't waste your money. Get diesel rated shocks and springs. The cummins is a beast.

 

What about adding a leaf to the new springs

 

Add a spring to diesel rated springs for sure.....I did on my skyjackers on my ol truck. Don't waste your money on gas springs for gas trucks.....