Which Universal joint do I have?

[mikes68charger]

I have an 8 3/4 rear end in my 68 charger, but I got a 489 case with a 391 pos. I know this case uses a bigger universal joint, is it the same as the dana?

[BrianShaughnessy]

One would assume it would be a 7290.   But after almost 40 years anything could have happened if and when pumpkins were swapped.  Keisler should have sent instructions on measuring the rear U joint for ordering the driveshaft.

[Rocky]

The U-joints for the 7260 are 2 1/8" wide, and the 7290 is 2 5/8"
If for some reason you had a 1350 series it would measure 3 5/8"

Brian is right too.The tech guys at Keisler are really helpful when you can get them on the phone.

[mikes68charger]

Yep after mesureing the 489 case 8 3/4 uses the same universal joint as the dana rear end. Thanks

[Just 6T9 CHGR]

Not nesssarily.....either case could have come with the smaller yoke (741, 742,489)
The larger yoke was used in HP aplications...its better to measure it just in case....