I want to switch out my 7.5 to an 8.8, is it truley a direct swap or do I need to get a new drive shaft and other parts?

 

true swap as long as its a 28 spline, and drum brakes.

 

i did that to my truck and it eas basicly a true swap but i replaced the the axel seals and the gears a while later.

 

I have a 97 2.3l 7.5 and went to a 04 FX4 8.8 rear. The problems i ran into were my stock wheels not fitting on the axle. I had to bore out the inside of the wheel to fit onto the axle hub. And the parking brake did not fit correctly. Other than that it was simple.

 

fx4 is a 8.8 31 spline axle, and sounds like you had 14in rims.

 

If i put 31's on my truck will the 8.8 help out

 

i dont see it making that much of a difference. Its when you get up to tires in sizes like 35s that will make you wish you had a 8.8. Just make sure your gears are good enough for the tires you will be running.