Mark, I have the Patrick's 3:55 gears in my truck..
To me it was the best money I spent on any part of the truck. The swap was pretty straighforward. If you are patient and can follow directions you should not have any trouble. You will need a dial indicator to set up the lash on the ring and pinion. I found the instructions in the shop manual easier to follow for that portion..
There is a picture of the disassembled torque tube housing on my web page, click on the link below.
Any other questions, let me know.
