Front diff swap

[1998 K1500 Bubbles]

Idk if this has been talked about before. I have a 1998 Chevy K1500 Z71 Silverado and I wanted to get a set of 3.73 gears for it but for the front diff it would seem simpler to just put a different front diff in. I find a lot of gmt800 3.73 front diffs but not many gmt400s. Would the gmt800 front diff swap into my truck or would I need to find a gmt400 one.

 

[b454rat]

Can't find one with 3.73s?? Too bad weren't closer I'd give you from my Yukon dirt cheap....

 

[RichLo]

With fab skills anything is possible, I seem to remember somebody putting a H2 front diff in GMT400. I am unsure of how much work went into that but try searching Hummer or H2 front differential or something on here.

 

[Alteca]

the axle tubes would need to be swapped out due to the mounting pad at a different angle. The rest is bolt on as far as I know.

 

[GoToGuy]

Are looking on line or actually looking at the trucks?
How different an angle , major or angled shim different?

 

[1998 K1500 Bubbles]

I was looking at pictures of them because I don’t have a gmt800 to look at but they look very similar. If all I have to do is swap axle tubes that would be nice. The other thing I didn’t know about is the wiring, I have a push button 4x4 so I didn’t know if the wiring would be different for the gmt800 diff. In Nebraska a lot of the places I’ve called said they don’t have any with 3.73 but had ones with 3.42 which is what I have now.

 

[GoToGuy]

Are you looking for any front diff or a 1500 only. Most of the light duty 2500s came with 3.73 like mine. Heavier capacity, higher gear ratio more often.

 

[boy&hisdogs]

3.73 is a very common ratio in these trucks, I doubt finding one would be harder than swapping a diff from a completely different truck.

 

[Sean Buick 76]

The chances of a 88-98 truck having a 3.73 are about 75%

 

[Alteca]

Are you looking for any front diff or a 1500 only. Most of the light duty 2500s came with 3.73 like mine. Heavier capacity, higher gear ratio more often.

did any “light duty” 2500s have an 8.25 diff?
Mine from a 400 burb has the mounting pad angled pretty severely maybe 45°? I’ve seen numerous 800 diffs and they were all either parallel to the ground or slightly angled.