I found an automatic truck that I'm interested in the only problem being its got 4:10 gears!! What would be involved in putting the 3:54 and how much should I expect to spend? Thanks in advance!

 

The 4:10s are one of the options [ 2 choices ] , it is for both AT & MT , more gearing for towing , but less fuel millage .
The cost can very a lot , depending on how you go about it , you could just swap the hole rear end , if you could find a deal on a good used one .
Your sig. does not say 2x4 or 4x4 , if it is 4x4 you would need to change both .
I have seen shops charge as much as $1,500 to do 1 diff. rebuild/gear change , most would say that they would not want to change gears without all the other parts , including bearings , or sign the work order saying no warranty .
Parts very , but I would guess not less than $800 for just setting up new gears .

 

I'm sorry the truck is 4x4! I had a guy tell me that swapping the guts out of the front and rear diffs in the truck could be done for less than 1K including all the parts! That sounded a little farfetched to me after seeing so many discussions on here! Thanks again John!

 

If you where closer I would swap with you. I am running bigger tires and want 4:10 gears.

 

My truck also has 4:10 's. I was also planning on switching to 3:54 's. Paying to have the gears changed was way more than I wanted to spend. I posted in 3 forums looking for someone fairly local who wanted to swap axles. I must have has 12 to 15 ppl with 3:54 wanting to swap. I decided to keep the 4:10 's so I could install taller tires.

 

I am also looking to swap my 4.10 /4.11 differentials for 3.54/ 3.55`s. I am currently spending the winter in Laughlin / NV. If anyone has a interest in doing this, that is within a few hundred miles of Laughlin....let me know.

 

I bought an an auto with 4.10s I was going to swap them, but I just put on the some 35" tires and all is well.

 

I also wish I had those 4:10's in my truck. I took a minute and played with an online gearing calculator for you. If you go to a 35" tire you'll have made up the difference almost exactly. Spend your $1500 on a 3" lift and some 35's rather than the gear swap.

John

 

Do the taller tires have the weight rating available , that the near standard sizes have ?
Might be something in mind , depending on how you work the truck .

 

I can not use larger tires on the duel rear wheels. Due to the load I carry, the sidewalls would rub each other where the tires contact the pavement.
I had contacted a number of different tire dealers, to get their thoughts on the posibility of using a spacer between the rims. Everybody I talked to, said it is not a good idea to use a spacer. If anybody has tried this...Please let me know of the results, good or bad.

 

Sorry, I didn't read your sig.