I just bought new 35 inch tires for my truck and everytime i just barely give it any throttle or go up a slight slope it down shifts, and it has been really bothering me. So i have been researching 4.10 and 4.56 gears and im trying to decide between the two, and i really have no idea what to choose. So i am just looking for anyones opinion on this. Also if i do change the gears would i also have to change the gears in the front differential if i plan on using 4wd?

 

i'm in the same boat as you...but i don't really have much down shifting, truck is just slow now. i've got 3.55s and when i did the little conversion equation, 4.10s weren't enough to put me back at stock and 4.56 was little bit more than that. I don't remember the equation exactly but i'm sure someone on here will. But, YES you will need to replace both sets of gears if you still want to use your 4x4 at all. If you do not and you put it in 4WD, you will seriously screw something up.

 

4.56 would be best.
And you'll need revers cut gears for the front.

Phil

 

Ok thank you, i just have a couple more questions. So what brand of gears would you recommend? And if i do get the gears changed would i have to get the computer reprogrammed to accomodate the new gearing?

 

4.56s for sure. Being that you have a 97 im pretty sure you have to get a new speedo gear. My edge will adjust for my 99 but I read somewhere that 97-98s need the gear.

Hey JD, which did you do first the Body Lift or the torsion/ lift blocks? I'd like to see some pics of your setup. I have a slight torsion crank with an aal but want more so I was thinking about a 3.5" lift block. Thanks and sorry for thread jacking

 

I'm running 4.56 gears, an went with Superior. But, I'm running 37's! As far as the speedo. They are right! 97/98's have to be re-geared thru the tranny with a new speedo gear. 99's an on are electronic, being why they can be done with a programmer!

 

did you have your speedo regeared? If so, how much did it cost, if you dont mind me askin? Sounds like a whole lot more of a PITA...

EDIT: and to the OP, Yukon and Precision are probably two of the best names out there but expect to pay a little more for quality. While i've never heard anything bad about Genuine Gears, i've heard sometimes they'll whine, which i'm not sure if that even effects their performance. Also, I dont think Motive and Ford Racing gears would be bad choices either.

 

I have 4.10 Yukons in my truck,,,and I'm very very hard on them! Never a problem.

Sorry,,,cant help with the speedo

Phil

 

I have 4.88's on mine with 35's and it works like a charm. It revs a little higher than usual on the highway but I plan to put 38's on eventually which will work perfectly. The speedo is about 10 miles an hour off but I figure when I put the 3 inch body lift and 38's on it should even off nicely.

 

I didn't even bother with the tranny gear. After awhile, you pretty much know where your at!

 

so thumper and ram air, since when you put bigger tires on with stock gears it shows that truck is going slower than it actually is, does this mean that if you put 4.56 gears or bigger the speedo will say your going faster than you actually are?

 

With my 4.88's and 35's when I am going 35mph my speedo says I am going 45 mph so you would be correct, yes.

 

Yes! What Thumper said!^^^^

 

thanks guys. now if only i could find someone that wont charge out the *** to install gears..

 

Ya I paid about 1700 for everything installed. Those are yukon's.