alright guys, new to the group, been reading a bunch of threads on here about gear ratio but so far haven't seen anything super similar to my truck. I have an 01 Silverado ext cab 5.3l, pretty bone dry stock except manifold back exhaust, CAI, and a laptop tune. truck now has 180k on it and im going to start building everything to give it a nice fresh drivetrain. it is on 33x1250 tires and aftermarket 18's, level lifted about 3". with that extra weight and the stock 3.42 gear ratio, it is nothing short of being a turd. I do some towing (car hauler with a couple atv's), but most of my driving is done in town, some hwy riding about once a week. I have heard I need to go with a 4.10 ratio but have also heard I need a 4.56. I want better performance and power, as well as to get rid of the ever annoying down shifting to find power and drive my trans temp up. daily driven vehicle, will be getting a few mods in the future, built tranny, small stall, and a built motor but nothing crazy, just a truck with a little power. what are yalls suggestions on the gear ratio?

 

I'd do 4.56 gears. 4.10's aren't enough gear for that tire and weight of the truck in my opinion. I just put 4.10s in with my 32" tall 420s and its way better than 3.73's but I also have a 4l80e which runs a bit higher rpm in overdrive than the 4l60e or I woulda done 4.30's. Plus I drive on the highway quite a lot so. If it's a true 33" tire, with 4.56's you'd run right at 2500rpm at 75mph.

 

If you plan on staying with the 4l60 4.10 will be fine if you go to a 4l80 then you need 4.56s.... Anything over the 3.42 will be better.... Ive had 4.56 behind a 4l60 and 4l80 and ive also had 4.10 and 3.73 behind both of them, for a dd i prefer 4.10s behind a 4l60... Just my 2¢ fwiw!!!

 

yea they are definitely a true 33" tire they are nittos. ive been doing a lot of rpm calculations and that's about what I have gotten as well, really not that bad. plus I definitely wont have to worryabout the constant down shifting as well, which of course gets 10x worse when I am doing my light duty towing. not sure yet whether I will go with another 4l60 or bump to the 80, still weighing my options there, either way whatever it is will be slightly built just for strength and performance, and peace of mind of course. I guess if it came down to it and I didn't like the 4.56 I still will have my rear end with 3.42 so I can swap back and put 4.10s in it. thanks for the input guys

 

If you want stock like performance go for the 4:10's if you want a "bit above" stock gear performance put in the 4:56's.......... I personally would install the 56's just my .02 as I have 4.88's in my Z71 on 35's and it is just the right bump in gear over feeling "stock"