Thought I had read that you decided on 4.88 gears before. I think the decision to go with 5.13 was a good one. I have never regreted the 5.13's. It's the best for the 37" tires. You'll be happy

 

Yes I did for a time consider going 4.88 b/c I am going to have plenty of gear ratio in the transfer case. It was going to be a bigger help with the pavement life for those. The push back to 5.13s was cost and tranny life with emphasis placed on loaded curb weight for a week long trip. I only had to buy 1 set of 5.13 rp. This is going to run a bit higher rpm on the road...but that's ok as I don't need to go that fast. As long as it's still faster then Heeps.

 

You'll be pleasantly surprised, the rpms really don't go that far up, my speedometer is nearly right on the money with the 37. Top end is only limited by the speed rating on your tires

 

Sweet. Thanks for that feedback.

Btw regarding the speedometer stuff...the tone ring for the D80 (if I found right) is only 110 tooth count (9.25 rear is like 108), so you really had minimal influence from that?

I've found that the D70 is 120 tooth count, which will translate to shifting early...and my plan is to reflash the PCM to correct tooth count.

 

That's interesting on the differences. Doesn't seem like that would make much difference. The reality is, with the stock rear axle the speedometer would read 50 when I was going 60 and now after the axle swap, I read 59 when I'm going 60. Not sure of the mechanics involved there but was very pleased with the result. My hypertech programmer had a correction feature for tire size but didn't seem to actually do anything.