oldred95

I'm trying to work a deal with a guy on a 14 bolt SF 6 lug axle. I know it uses a 1350 u joint so I am either stuck with using the bastard conversion joint or if the donor truck configuration happens to be right, getting the drive shaft from it as well. But is a drive shaft swap really worth it to upgrade to 1350 u joints? The cap size is only 1/16" bigger so I wouldn't think the cross is all that much beefier but I've been wrong before. I currently have a stock two piece steel drive shaft with original 204,000 mile 1330 u joints. Worth it or just use the conversion joint? In a perfect world I would use the big 1 ton u joints, I believe they are 1410s like the Duramax trucks use.

hog

You can just use the yoke off of your 10 bolt then you dont even need a conversion U-joint.
But if you are swapping to a 14 bolt 9.5" SF you must be doing so to increase strength, so it only makes sense to upgrade everything. But I dont see you having breakage problems with your current setup and the 1330 joints.

peace
Hog

oldred95

Really, a 10 bolt 8.5 yoke will work on a 14 bolt 9.5 pinion? I did not know that. I figured the 9.5 inch pinion would be bigger. That would be a very simple option. I would like to stay as far away from aftermarket u joints as possible because they just don't last like the originals.

They say the 2 piece steel shaft is stronger and I don't doubt it. At one time I thought having 3 u joints would make it weaker just because there are more points to fail but really with 3 u joints it would spread the load out over the 3 and allow it to handle more abuse then just 2 u joints, would it not?

The reason for the 14 bolt is I don't want to break anything. I've got a perfectly good 10 bolt with 3.73s in it now and its worth more in working condition than as a rebuilder. Within the next year I will be needing tires and I've been wanting to throw some 4 inch lift spindles on it anyway and a shackle flip so I'm thinking 35 x 13.50s are in order. The tire and wheel package will weigh just over 100 pounds a piece and the way my 80E shifts I just don't see a 10 bolt holding together.