Just got a quote to change my gears and have my limited slip rebuilt, plan on doing it early next week. Right now I have a 4.0 with 3.55s on 32s. How many of you are using 4.30s? I am torn between 4.10s and 4.30s right now. My rationale is that stock 4x4s come with 4.10s and 31s. So I should get 4.30s for my 32s.

Let me know what you guys think. I'm exited to finally get new gears, been crawling around with 3.55s for some time now.

 

Nobody with 4.30s?

 

I've never heard if 430 I'd you have 32.5 I would do 456 gears that's what most do for 33 s which is perfect

 

4.30s are available for the 8.8 and moving from 30/31s to 33s they are calculated to be the right gears BUT most people go to 4.56s and get it over with AND just in case 35s are in the works somewhere.

Calculate it out… 4.30/3.55 = 1.154, the change for the gears 3.55s x 1.154 = 4.096 or 4.10s not 4.30, so you are going deep.

4.10s should give you the OEM feel back with 32” tires.
4.30s will give you the feel of more power when taking off, sort of a kick in the @ss but will run the rpms up on the engine on the highway.

If your truck is 2x then why go deep unless you are racing it or want more seat of the pant feel, if a 4x the deeper gears will give you more power on the trail.

An idea, I know this is work but find a friend with 4.10s in their truck, swap your tires on and try it out for how it feels both around town and on the highway, just to see, then make your call.

 

i ran 4.56's on 32's with great results. i now am on 33's. i run about 2400 rpm highway but i get 600km to a tank.

its not about RPM, its about engine load. at highway speed i just barely have to rest my foot on the gas. My truck at 60mph is at 42% engine load. when i drive around town with my 4.56's im at 55% normally. Engine working less uses less fuel.

If you plan on ever going to a 33' get 4.56's. if you drive 75%+ highway, get 4.10's or 4.30's.

 

Great information, thanks. I think after that calculation I am going to do 4.10s. I don't do a lot of offloading and I am 2wd. I do a lot of highway driving so maybe 4.30s aren't for me.

I just can't wait to get rid of these 3.55s.

Also I never thought about swapping tires on to another truck. I have a buddy with 30s and 4.10s so maybe I'll ask him. It's gonna look like a dragster with 32s in the back and 30s in the front haha

 

You switch all of them around not just the back

 

or your abs wont be happy.

 

4x4 you have to put on all four tires or you will damage the transfer case. or you can pullout the front driveshaft... but tires would be my first choice

 

It's a 2wd, but I'll just swap all four. I'll be doing it this weekend. Ill let you guys know how I like the 4.10

 

Just cause its a 2wd you still have to rotate the tire it doesn't matter you still have to swap all

 

It’s all about RPM, which in a way is what you are talking about LOAD...
When you build an engine for frag racing you determine the tire size, the cam working range and then you gear the vehicle to turn max HP rpm when going through the lights. This same thing applies to an everyday vehicle, determine where the engine is making the best torque or for more performance where the high HP is coming in and that is where you gear for.
If your tire size is set then the only thing in a DD that can be changed are the differential gears.
In a 2WD, as the OP has, you only need one set of gears but in a 4WD you need to change both the front and the rear gearing.

IF running 3.55s, your cruising speed at 60 your rpm will be a lot lower than running 4.30 gears and you need to determine where you optimum level is so you can drive comfortable, not over-rev the engine, create unnecessary noise and burn too much gas.

It’s easy, where does you engine makes the best performance, which is where is will get the best MPG, determine that and what speed you want to be going when the engine hits that rpm and you can gear the vehicle accordingly.

Sorry if this is confusing, my way of talking and writing, not good that is.