Anyone know if the 99+ IFS front ends are the same as the 88+?

[Russell]

I have a 96 GMC K1500 daily driver with a set of 3.42 gears, and an open rear diff with drum brakes that don't work properly unless I constantly manually advance them

I also have the remains of a 2000 GMC K1500 with a set of 4.10 gears, a rear locker, and disk brakes out back.

Does anyone know if it is possible to bolt the IFS diff from the 2000 into the 96? How about the spring perch width between the two trucks, are they the same or totally different? Could I take the master cylinder from the 2000 and use it on my 96's booster to have a properly working disk / disk combo?

The 96 does have ABS, would it get messed up by running disks in the rear instead of drums?

How about the e-brake stuff? My 96 is a standard, so the e-brake is a real asset....

If I am totally off my rocker, lemme know, but if this is something that I can accomplish, I'd like to do so once my semester finishes. The 4.3L just doesn't quite have the gusto I'd like, and I thing the 4.10 gears would do it a ton of good, not to mention the good that gov-loc would do me in the winter...

[smirch9]

If it was a 99 I think it would work, but since it is a 2000 it is different I think. ABS will still function properly and u will have to modify the e-brake to make it fit the disc brake set up. Have u considered just swapping the drums for discs? What about pulling the gears and swapping those to?

[Russell]

I crawled under my 96 and took a look at how it is mounted, and it appears to be identical to the 2000's front end... drain plugs are in the same place, casting looks identical, and the mounting places are all the same. The only significant difference I could find is how the outputs looked, on my 96 they are round, on the 2000 they are sort of shaped like a flower. The bolt pattern looks the same regardless, just a bit less material on the 2000.

The rear diff is a direct bolt in, the springs are the same length, and the perch is the same width. The e-brake cable from the 2000 appears to be the same as on my 96, so I think I might be alright there too

I suppose it is close enough to be worth the effort to pull the diff from the 2000 and find a 88 - 98 with the diff pulled to see if it'll fit. If it does, and if the electrical stuff is all compatable, I'll make the swap over christmas break. 4.10s with a locker and good rear brakes would be wonderful

[Russell]

I had 20 minutes today to spare, so I pulled the diff out of the hulk. It was actually really easy to pull, only took about 10 minutes from start to finish. Winds up the diffs are indeed the same unit, but there are two significant differences. First is the mounting bracket on the passenger side of the diff, on the 2000, it is flat, and on the 96 it is at an angle.

Second difference is in the the way that the output shafts are sealed.

The passenger side axle tube unbolts from the rest of the diff housing, and is the same length etc as the old one. If I can bolt an old style passenger diff housing up, and use the old style axle, the diff will bolt in no problem.

So, I am going to wait and see if I can find a free IFS diff from an 88-98 truck, and make the switch after I get everything changed to the way I need it, have gotten a new master cylinder, and have found out exactly how I'll bolt the e-brake up.