Good Morning from Central Arkansas....I'm working in a 70 Plymouth Satellite,I'm needing to change the gears ..it has currently a very worn sure grip with 290 something( please forgive my forgetfulness here) and I'm wanting to put in some 391s( not sure grip) ..and although a Mechanic of many years..have never opened up a Mopar third member..but I was told that my 391s wouldn't work in my current 3rd member...If more Info is needed for help..let me know please..thank you ...Dan H

 

https://www.doctordiff.com/drivetrain/mopar-8-3-4/

https://www.justdifferentials.com/CH.../npdoc8.42.htm

 

Thank you,that helps me..differentials is an area I've not gotten into in the past,and I've learned in my 49 years to ask questions ..thank u again

 

I installed an Eaton Detroit Truetrac differential in my Satellite. Does not require special lubrication or friction modifiers. Very happy with it.