I have an '89 2wd with a 727 and a 3.07 rear end. Should I get a GV OD or replace the 727 with a 47RH? Trying for less rpm at freeway speed. The locking convrter would be nice too...

 

You already have a very high rear end. Are you sure you want to go higher still? I think the 46RH was the tranny in my '93. It had the OD and might be the tranny for you. I had the 3:54 rear end in mine and I put oversized tires on it. The performance was noticably less with just that little bit of ratio change. If you get too high the performance will be very sluggish and won't help mileage a bit.

John

 

I respectfully disagree. Adding OD and keeping those gears is fine and IMO a great idea. The diesel torque will overcome the gearing like a gasser would not. Milage will likely increase a bit, especially if you added lockup converter.

 

I love my 47rh. Having a TC lock-up and an OD is awsome. I would say that I gained a couple mile per gallon but havent done the math yet.

 

I am working on a 518 OD for mine and the ultimate goal is to do a 47RH later down the road. I'll have questions eventually...

 

I'll put another vote in for a 47RH, having OD and a lockup converter will make it nice at highway speeds.