Correct U-Bolt Length for 8-3/4 Rear End

[Chatt69chgr]

Mopar Performance lists three different U-bolt/nut packages.  7", 8", and 9".  Is 7" the correct one for a 69 Charger with 8-3/4 Rear End?  I think it is but would like to confirm this length with someone who has bought and used this package before I go order one.  Thanks.

[Just 6T9 CHGR]

The length depends on the leaf springs you are running....base model 5 leaves per side, Hemi springs 6on left 7 on right bias springs etc....

[firefighter3931]

The length depends on the leaf springs you are running....base model 5 leaves per side, Hemi springs 6on left 7 on right bias springs etc....

The base spring package will use a 7in u-bolt. If you run an xhd or SS spring you will need longer u-bolts. I just went through this trying to bolt on a set of SS springs and the 7in u-bolts were too short. I went with the MP 9in u-bolts but i'm pretty sure the 8in would work.



Ron

[Chatt69chgr]

I am buying the Mopar Performance standard springs, not the superstock kind. P4452982 and 83.  I looked at my car now that has the 8/14 rear that I am replacing with 8-3/4.  It has 7 inch u-bolts with maybe an inch of thread showing below the nuts.  And it does have 5 leaves each side.  Both housing tubes are 3 inch dia.  So do you think that the 7 inch u-bolts will work with the new springs I am ordering?  And I am not planning on reusing my old ones.  I am going to buy new ones.

[is_it_EVER_done?]

I always buy them much longer than necessary because it only takes a couple minutes to cut them off with a cut off wheel, and any that are "proper" for a particular application, are too short if you end up shimming the rear end for pinion/driveshaft angle.

IMHO, there is no good reason to not get the long ones as the time saved in not cutting is minuscule, and the re-buying longer ones, or not adjusting proper pinion angle (or other adjustment) due to the fact that the "proper" bolts are to short, can hurt your feelings for a long time.

[Chatt69chgr]

Thanks.  I see what you mean.  I guess the only thing you would have to worry about would be running out of threads since I don't think they are threaded all the way up as it were.

[firefighter3931]

Thanks.  I see what you mean.  I guess the only thing you would have to worry about would be running out of threads since I don't think they are threaded all the way up as it were.

Chatt, the MP 9in u-bolts are threaded 3/4 of the way up....no need to worry there. I agree with isiteverdone....much easier to cut bolts that are too long than have them too short. I just went through this with mine. I didn't buy the original set of u-bolts....they came with the Dana 60 i had built for the car. It helps to have some added length in case you need to shim up the pads for correct pinion angle as mentioned above. 



Ron