At the moment I have 265/75R16 which is close to a 32x10.50 with the stock 3.55's. It runs pretty well. If I go with the 35's though will I really need to go up to 4.56's? I mean I can see 4.10's but 4.56 just seems like a big jump to me. I will be doing interstate driving quite a bit and I pull a boat multiple times over the summers(not on interstate). What kind of rpm's do you guys see in the 80-85 MPH range?

 

well with my 4.10's at 70mph with OD on im at about 2350 or something right around there. Honestly just go with 4.10's and you will be happy with them man.

 

I appreciate the help y'all!!! Thanks!!

 

4.56 gears and 35 inch tires is the best combination for running stock rpm for any given speed on these dodges. youll find your transmission downshifting all the time with anything less, especially if you'll be towing with it.

 

i guess i didnt take into account though, that you'll be running those speeds. these highways in nebraska are 60 mph tops. I believe im running around 18-1900 rpm at that speed with my setup, which is lower than i want to be.

 

Ok guys, I've been playing with the calculator on randy's ring and pinion and have realized the numbers aren't that different. See the issue I'm having is I'm not sure the 35's will clear and don't want to overgear if I end up dropping to 33's. The difference in 35's with 4.56's and 4.10's at 85 MPH with the 0.69 OD ratio is 259 RPM. The 33's are a 275 RPM difference. All four combinations range from 2308 (35's with 4.10's) to 2723(33's with 4.56's) RPM. Considering I make the 250 mile interstate run twice about every three weeks. The worst case scenario of 2723 RPMs isn't really all that bad is it? Will I be able to make up for this while running around town?

 

Don't run 85 miles an hour.......

 

I don't experience any such downshifting you speak of. Not saying it can't happen, but I wouldn't pitch it as across the board. I would say that 4.10 with 35-ish tires is just getting into a good balance. I don't tow, which is a good point you bring up. Freeway I'm typically 70, putting me roughly 1900-2000 rpms in OD.

 

Is there a reason you say this?

 

Also 2750 RPM isn't out of the safe RPM range is it? Considering this is just while I'm going home from college and returning once every three or four weeks. I'm not constantly going 85 but it ranges from 70 to 90 and I don't want the truck screaming at me while I'm being passed.