So I swapped from 3.55 to 4.10, I brought my gps with me to see how far out the speedo is. Ok it is reading correct. The rpms are higher so the gears were actually changed. Why is the speedo right? When I uped the tires the speedo was out and the stealership reprogramed the truck. The shop was closed by the time I realized I had questions about this so maybe someone here can answer this. Thanks

 

On your year the speedo is taken off the rear ring gear.
You only have to adjust for tire size on that style.
The older trucks (pre 98) take the speedo signal off of the drive shaft. That style requires recalibration for tires AND a gear ratio change.

Enjoying a performance increase with the new gears?

 

THANKS! Nice that I saved a few bucks by not having to mess with the speedo. The gear swap was far less dramatic than I expected, my RPM jumped maybe 500. I run 285-75-16s so I don't have true 4.10s more like 3.90 ish. I'm looking forward to towing with the new gears because the 3.55s really didn't cut it with the larger tires.

 

Probably not too much fun in the mountains with the stock ratio, eh?

Never been to Agassiz, but I'm supposed to teach a course in Chilliwack in a few weeks.
Beautiful country BC is...

 

Unless I'm going South I have to go over a mountain range. The tranny is the weakest link so I hope this will extend the life span. This is such a great area, close to the states for shopping/camping and a mild climate. Agassiz is across the river, about a 20 minute drive from Chilliwack. housing is a little cheaper and it is closer to work for me.