New gears and posi installed

[JKmotorsports]

I installed my new posi and gears this past Fri night in time for the Houston meet. Stayed up til almost 5am throwing the stuff together then re-installing the rear back into the truck just to make it to the meet.
Anyway, I went from 3.73 to 4.56 and also installed a TrueTrac diff to replace my G80 I shattered. HUGE difference in acceleration with the new gears. Highway cruising isnt too bad. I'm running just under 2100 rpms @ 65mph. I noticed my gas mileage actually increased with the new set. The gears are so much deeper than the 3.73s that I thought my mileage would suffer, but seems like I've gained roughly 60-70 miles per tank on my round trip from Austin to Houston this past weekend. Trying to turn these heavy wheels on this truck used some gas, but now with the lower gears it doesn't need as much pedal to move.
I sprayed a couple pieces while I had the rear out also.
If I wasn't on such a time constraint, I would have taken pics and done a write-up on the gear and diff install.

 

[Young28]

Sweet. I bet that thing is fun to drive haha

 

[iwaslowr]

I was skeptical about the gears too but I'm glad they are streetable. Interesting how your mileage increased, that is icing on the cake!! Any plans for going to the track?

 

[blueflamed03]

wow...all the way the 4.56's, I bet it pulls GREAT now huh?

 

[puckhead]

Glad you got it all fixed up! Wish I woulda upgraded when my rear end went out. Oh well!

 

[Max]

Damn I think I'll go 4.10s when I swap in a trutrac. What size tire are you running, 32" tall? 4L65E still?

 

[Spooner]

You running stock axles?

 

[Robert.K]

Alot of info would be helpful on this! I plan on doing the samething in about 2 weeks and was about to start a post on it. I want to do the 4.56's, running stock 3.73's right now. And was also looking into a trutrac. i never use my 4wd but i guess it wouldnt hurt. Just dont want to waste money or do something stupid and have to spend more money to fix it. Pushing no where near to power you are, but thats in the plans too. Pro and cons would be very appreciated. ( plan on running 26's or 28's versus the 24's I have now). Your in Austin right? Im in Ft. worth on business for the week back and forth to dallas.

 

[rich5368]

You know the mileage makes sense to me. My brother found a calculator (I'll try and get a link) that takes your wheel size compared to your gear size as compared to stock. I don't remember the specifics but on my brothers subirban with stock 4.10s with 20"wheels it equated his truck to running on more like 3.55s. So 4.56s with 22s or 24s and on the highway you'll be close to running "stock perameters." Makes sense as at 75 i'm turning about 2300 stock on 3.73s and on 20s with 4.10s he's turning about the same.

 

[JKmotorsports]

I was skeptical about the gears too but I'm glad they are streetable. Interesting how your mileage increased, that is icing on the cake!! Any plans for going to the track?

Last time at the track I ran it with the 3.73s, on the 24" street tires, full interior and stereo system, and my bro riding shotgun with the vidcam. I left the hole at only about 3/4 throttle for about the first 40-50 ft or so to keep the tires from spinning so bad and pulled a 12.80 @ 105.9. I wanted to go back for a 2nd run w/o my bro and a little more gas off the line but i didnt have a helmet with me so they wouldnt let me run again.
I'm trying to find a different set of wheels for the track and run a set of slicks so I can launch full power w/o spinning. Slicks, lighter wheels, a little less weight, 4.56s, and leaving the hole under full power w/o traction issues should make a big difference.

wow...all the way the 4.56's, I bet it pulls GREAT now huh?

Damn I think I'll go 4.10s when I swap in a trutrac. What size tire are you running, 32" tall? 4L65E still?

If I was rolling a shorter wheel/tire combo i would have went 4.10s, but these 4s are 32.5" tall and I wanted a little more off the line. And i'm still running the performabuilt pro-race 4l60e.

You running stock axles?

for now...