I have a 72 Duster 340 w/ 727 auto and 8 3/4 rear. I was looking to get a set of universal joints for it (front and rear of drive shaft). In looking to order them, I have a choice of 2 sizes. (1) 1.078 Inch Bearing Cups (2) 1.126 Inch Bearing Cups. How do I tell which size I need before I order them?

What is the difference between the Chrysler 7260 and 7290 series?

The 7260 and 7290 series are the two sizes that are commonly found on Chrysler products. They represent the two stock sizes that have been used for many years. The 7260 series is the “small” Chrysler u-joint size (2 1/8 inch between flats on yoke with 1.078 inch bearing cap diameter) and the 7290 series is the “big” Chrysler u-joint size (2 5/8 inch between flats on yoke with 1.125 inch bearing cap diameter). The 7260 series is similar in size to the 1310 series and the 7290 is similar in size to the 1330 series. They both utilize the inside “C” clip design to hold the u-joint within the yoke flats whereas the 1310 and 1330 use the outside snap ring design.


This from denny's drive shaft web site. Generally the small block cars used the small u-joint. Hope this helps.

Thanks for the info!

'72 340 A body got the 7260 joint, even the 4spd cars.