A very expensive and dumb mistake

[Ole Buck]

finally mocking up the drivetrain after setting the engine transmission and transfer case and then I saw it. I guess I just got excited about doing a one ton swap into my 87 square and just simply bought the wrong rear end. I already have 5.13 gears, arb air locker and disc brakes.the spring pads have been cut, moved and welded to fit my truck and it will not fit. I am sickened. I want to throw up. I am off the complete width of my driveshaft. This rear end is offset and not centered like I need. Will someone please tell me exactly what 8 lug full or semi float that I need to make this work please.
Here is a picture of my bowl remover.

 

[bucket]

Why not just try running it? I can't think of what they were off hand, but I know there have been factory built trucks with an offset pumpkin.

 

[Ole Buck]

Why not just try running it? I can't think of what they were off hand, but I know there have been factory built trucks with an offset pumpkin.

It would be way off center. This rear came out of a 03 2500 I believe. The yoke and pinion are off set instead of centered like I need. I don’t know what I was thinking. I had no idea it was like this.

 

[Ole Buck]

Talked to the original owner of the rear end. Said it was perfectly normal to be offset by that little bit. No issues at all when he ran it on his K30. Same transmission and transfer case. Just got to use the bastard u joint in order for my driveshaft to work properly. Bucket you were right!!

 

[nvrenuf]

All 14 bolts are offset like that and are in literally millions of squares. Don’t sweat it and run it.

Just to say it out loud, since the spring perches have been moved you might double check to make sure the housing (not the pinion) is centered under the springs.

 

[ali_c20]

All 14 bolts are offset like that and are in literally millions of squares. Don’t sweat it and run it.

Just to say it out loud, since the spring perches have been moved you might double check to make sure the housing (not the pinion) is centered under the springs.

I have to measure the 14 bolt ff in my 74 C20, it looks pretty centered.

 

[CalSgt]

Talked to the original owner of the rear end. Said it was perfectly normal to be offset by that little bit. No issues at all when he ran it on his K30. Same transmission and transfer case. Just got to use the bastard u joint in order for my driveshaft to work properly. Bucket you were right!!

So long as the angle at one joint matches the angle at the other it’s all good! No different than the downward angle from the trans to the pinion. I suppose it could make the phasing of the joints more sensitive to pinion angle.

Pinion and transfer case are both parallel to the frame rails, so angles at the joints match.

 

[bucket]

All 14 bolts are offset like that and are in literally millions of squares. Don’t sweat it and run it.

Just to say it out loud, since the spring perches have been moved you might double check to make sure the housing (not the pinion) is centered under the springs.

It kinda seemed like the entire pumpkin might be shifted over a bit? I dunno, I guess I've never paid much attention to how much of a side angle a factory shaft does or doesn't run at.

 

[ali_c20]

Back from the garage, yes the pinion is offset. These are the measurement from my 74 C20.
I measured from the inside of the spring perches.
Perches to pumpkin: D: 8.2 P: 12.4
Perches to pinion: D: 20.65 P: 19.5
I learned something today as often in this forum

 

[Grit dog]

Back from the garage, yes the pinion is offset. These are the measurement from my 74 C20.
I measured from the inside of the spring perches.
Perches to pumpkin: D: 8.2 P: 12.4
Perches to pinion: D: 20.65 P: 19.5
I learned something today as often in this forum

Yes but that’s less than an inch offset so effectively less than half inch offset in the driveshaft.
If the OP pic is 100% correct, it’s off by about 2”. Seems excessive to me too. However at this point I would 100% bolt it up and send it and see how it feels and if good, see how long it lasts.
Again, context. It’s an old truck. If it’s going to be daily driven and u joints only last 10k miles, maybe it’s not acceptable to replace them every year or whatever.
If it’s like my trucks, a 10k mile u joint will be g2g for several years at the rate they get driven.

 

[Nardulli]

If the delta is too large, you might go to a 2 piece drive shaft. Take up half the offset output shaft to carrier bearing, and the rest carrier to diff yoke.

 

[Tonimus]

Send it. If you've got 5.13 gears with an airlocker, you're not running at 85mph. I don't think you'll have any problem with it.