optimal gearing with motor replacement
 

Thinking about dropping a HEMI in 2010 six speed. I have 4.10s now and was wondering if they would be good with the new motor or hurt the new motor performance. It is my daily driver.

Wondering this as well. I was going to put 4.88s in my 2011 JKUR with 35s but want to do a Hemi swap. Subscribed....

Haven't done it but the way I understand it, the gearing choice has to do with the trans not the motor choice.

I did a hemi swap and went with the 4:88 gears on 37's with a 6-speed. It is working very well for me.

I think it has to do with both, tranny and motor. You want to have your RPM in the optimal spot for a given motor. And RPM is dependant on tranny and diff gearing.