OK...so i am learning as i go. Turns out my truck has 4:10 gears instead of 3:73's. I was told when i bought it that it had 3:73's, oh well buyer beware I guess.
So my question is, what kind of cruise rpm can i expect with the 4:10 vs the 3:73? lets say at 70 mph.
Also, what decrease in fuel economy is there with the 4:10 ratio?
Kinda bummed out about this,Somebody tell me that 4:10's are great!!![:'(][:'(][:'(]

 

4:10's are great for off the line performance as well as pulling and towing, however you shouldn't expect this thing to be so great top end. The 4:10s will kill your fuel mileage too. They will pull down the side of a mountain when paired to the right motor too.

 

a 410 has 1 purpose..to PULL...forget performance/mpg

 

What year is your truck? I just wanna find out if you have a 3speed (TH350) or a 4 speed (4L60) or a manual.When I had my 04 crew cab Z71 (four speed) (4.10's) I could run 75mph at about 2400rpm's.

I averaged 16mpg on the highway on a 1300 mile trip between Ohio and Wyoming(I was hauling a longblock 355,two 12" wide tires and rims, two 6" wide tires and rims, and half a bed full of toys from my sons first birthday party.)

 

Nate's pretty much on the mark. I have 4.10's with 6.0 3/4 ton 4x4 and I'm usually around 2300 to 2500 (I've got a few hills in my area) and last time I took it out on the interstate I got around 13-14 mpg. I just put a TBS on and I can tell a big difference in my throttle response and it seems like I'm getting better milage, but I'm not sure. I'm heading to Kansas this weekend so I'll know what I'm getting with the TBS and I'll let you know. I'll probably do the throttle body bypass after I go to Kansas......

 

I forgot to mention that if you're going to be pulling anything heavy on a regular or semi-regular basis - don't swap out the back end. Argon's right, as usual, you can pull all day with 4.10's and a good motor. I've got the 4speed auto on mine and I pulled the bigger track hoe that Bobcat makes up a hill from a dead stop - kept up with traffic and the pedal wasn't ever near the floor.

 

My truck has the 4l60e auto 4spd. I came across a formula once where you can figure out rpm given a certain gear ratio and tire size. So as Nate says,if 4:10's give you about 2400rpm at 75mph what would the 3:73's spin the motor at given the same speed?

 

Im not sure about the 3:73 but the 3:42 which is what my z-71 1500 has at 75mph the rpm is at about 2000 to 2100 rpm. If this helps any. Thanks

 

the 342 is gone...it was about the perfect balance rear end...

 

What was the last year for the 3:42?