Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
This is my daily driver. It feels like it could use a taller gear but I want to be able to cruise at 70 or so. Will I be alright? And will I have to get a new carriers for the 4.10 gear sets?
I have 4.11's with 33's and it is just a bit low. You will have to use OD on the hi-way or you'll be reving above 3. Carriers should be the same /forums/images/graemlins/thumb.gif
It will be fine. I drive a 99 GMC 1ton full size van every day. It has 4.10 rear with 265/70/16 stock. At 70 that thing has just started to get going. /forums/images/graemlins/ignore.gif
My wife's DD is a Jeep Grand Cherokee. It came stock w/ 3.73s and 215/75/15s. I'd say you'll be fine. It has full-time 4WD and a 318 (5.2) and gets 18 MPG on the highway all day long. However, stop & go uses a lot of gas.
With 285's 4.10's and a 4l60E? you would be turning approximately 1800rpm at 60mph, 2100rpm at 70 mph, 2400rpm at 80mph. IMHO this is well within DD range. I doubt mileage would suffer much if at all. My 99 Yukon has 3.42's and 285s It needs at least a 4.10, I might even go 4.56 (2000rpm at 60, 2330rpm at 70) if you plan on anything bigger than 285s in the future.
Thanks guys! This site is the best for quick and accurate info! I bet it will actually help my transmission out. I plan to stay w/ 285's; they get me where I need to go and I can still fit in parking decks!
I am going to get an electric locker while I'm at it and go w/ the 4.10's.
The stock tires on a Sub/Tahoe were right about 30 inches tall. 285/75R16's are about 33 inches tall. 3.73:1 was the lowest gear that GM would put in the half-ton Subs and Tahoes. At 65 MPH, a stock truck with 3.73's and 30 inch tires would be turning 1900 RPM. With your 285's and 4.10's, it would be 1899 RPM at 65. /forums/images/graemlins/cool.gif So you'll end up with performance equivalent to a stock rig with 3.73's.
4.56's will only raise the RPM to 2112 at 65. A 4.10 setup with 30 inch tires would run at 2089 RPM at 65, so 4.56's with your tires would be pretty close to a 4.10 setup with stock tires.
I'd seriously consider the 4.56's, to make the truck a bit more fun to drive. /forums/images/graemlins/pimp1.gif