10 to 13 speed

Biggest benefit is 300 rpm drop between top gears instead of 600 rpm. I would swap one everytime.

 

If you primarily run on flat ground I don’t think you’ll really see any difference or advantage depending on what speeds you typically run and rear gears. If you run in hilly or mountainous conditions, then the 13 is definitely the way to go.

 

I run mostly flat and wouldn't want to go back to a 10. I wouldnt swap one just because. But if it was out and needed rebuilt, absolutely!

 

No way I would ever go back to one either. I’ve had an 18 in my last four trucks, I wouldn’t go to a 13 after having an 18 either.

 

New drive shaft

 

Just needs to be shortened

depending on the model the 13 speed could have a lower low gear and a taller, shorter, or equal to OD of the 10 speed.

I would absolutely scrap the 10 speed

 

And surprisingly, I missed the 13 more on the downhills than the climbs, back when I ran a 10 for a while.

 

May be I'm missing something here I've had this 10 speed with a 370 final drive since 1997 no problems. What gives?

 

I'm mixed on this. Drove many 18's and split the bottom when really heavy. 100k gross and 13 works just fine for me. But I do no off road work. Most people are just fine with either.