I dont think that your RPM level would be that high. From what I have seen on trucks with a 4.1-1 gearing, you can almost expect a bout a 400-700 RPM increase.

 

So, do you guys think I should just go ahead and try out the 4.10 gears or no? Should I just get 3.90's just to be on the safe side? How can I tell what I have in there already?

 

That dealer's an idiot. No offense, but if he doesn't know the OD ratios and threw 3500 rpms out, you don't want to be doing business with him.

unless you've go those stupid 10" diameter rims on your truck, you aren't going 3500rpms on 4.10's

I'm running 4.10s on 265X70X16's and seeing about 2400 rpms at 70-75 mph.

 

come on aim4, don't hold back.
Tell us what you really think!





p.s. did you read about my shift cable and the dealer?

 

like i said i have 4.10s with 33s. 2k rpms at 70, at 75 im at 2200-2300 its really not that bad.

 

I have the stock rims that came with the truck if that means anything. 245 tires. I'm just worried that getting the 4.10's would be a mistake.

 

Terranova,
First of all run from that differential shop that told you that your RPM's would be 3500. Then click on the link below. You will need to know what trans you are running, what transfer case you have and tire size. The chart will let you put in you stock numbers then put in what you want to upgrade to and compare the two. I hope this helps.

http://www.grimmjeeper.com/gears.html

 

Hmmm I have no idea where to look for these things. My truck didn't come with the owners manual so I guess on most everything lol. Thanks for the link though ill try to figure it out.

 

No, where's it at?

 

If you have the 5.9 you probably have the 46RE trans and a NP231 Transfer case. I tried to search but not a lot of good info out there. Most transfer cases have a tag on them and it should tell you what it is. Or you can go to the dealer and give them your VIN and they should be able to tell you. This should give you a place to start. A quick search on google will help you look for identification marks on your equipment to properly identifiy you stuff. Good luck