Hey guys. I have a 99 ram 1500 5.9
i currently have 33s on there. Which look pathetic lol
I want 37s a lot of people say might as well do 40s. And im like no.. I want 37s and ill be happy with that. But. My gearing is 3.5
should i change it to a 3.92? Or whatever is next to it? Im not a genius on gearing so advice would be great. And i dont want to lose power or barely move when i hit the gas.

 

If you are planning to install 37" tires, I'd suggest going with 4.56 gears. Whatever you do, ensure that you install gears for whatever oversize tires you are going to install. Also, if the truck is a 4x4, the front gear ratio must match the rear gear ratio. Here is a sample gear ratio calculator that can help with your choice.

https://www.summitracing.com/newsand...tio-calculator

 

Maybe even 4.88 or 5.13. Depends on what speed you're going to drive.

 

37's on half ton axles are going to EAT differential parts...... If you off-road with it, you are going to break stuff.

 

I will come in here (and this is all friendly please don't take offense) I had 37s on my 05 1500 and went through CV joints like we breathe air and even went with an aftermarket company CV joint that is suppose to be "Bulletproof" (RC or RV was the company). Still happened. Was the first and last 1500 I owned with CV joints. Now I run 37s on a 98 1500 and so far haven't broken anything. There are guys that say I went 10 miles and my wheel bearings are bad and then there are guys running 37s on factory wheel bearings. It's I guess on the quality parts you buy. But if you are running that size you should be aware things will break as they aren't designed for that big of a tire. If the OP has the money when something brakes upgrade it.

 

With a 5.9l I would go 4.88. I had 38's on my 2500 with 4.10s and those felt much too tall and its a v10. Not to mention your 46re will thank you going to 4.88, probably better fuel economy around town as well.