Well, I have a 3.0 auto so I guess what I say has to count for something.

I think my truck was geared perfect with 4.10's and 33's.

Now I think it is way overgeared with 4.88's and 35's, I am at 2600rpms at 70, 3100 at 80...thats VERYhigh. I also feel my truck was way more powerfull, towed a trailer easier, and it definetly got 2mpg more when it was on 33's and 4.10's (still double lift, only thing that changed was tire size).

I wish I would have went with 4.56, but I'm going to 37's, so I will be happy with the 4.88


For your truck if you really "need" to regear your current axle instead of getting an 8.8, I'd say go to 4.56, it seems like you wheel it a little and if you ever get 35's, you'll be happy.

I would just swap in an 8.8 w/ 4.10's...see how you like it (you'll probably love it), and if not, you can go 4.56 or 4.88.

I'm sorry, but 4.88 and 33's??? Have you ever ran that setup? I did and I thought I was going to blow my motor because I had to rev so high just to get out of a stop light. I actually felt like I LOST power because I had to mash the gas so much. Not to mention 9mpg....not cool. I think 4.10's and 33's is perfect.

 

If he wheels, he definately wants 4.56 gears. Wheel speed and rpm's is key when wheeling.

 

Maurice, "he" is a girl. lol

Brenton

 

SHHHH...you weren't supposed to tell maurice that ;0)

 

Dangit! Now here REALLY comes all the leg humpers. haha Including me.

Brenton

 

geeze....

 

guys, the week point on the 7.5 is the spiders, its common knowledge, ive run 33's on my old 87 with a welded rear. when a 7.5 goes its usually a spider failure or a crosspin failure, welding them up eliminates that stress, same as runnin a lunch box locker. ALSO, with keepin the 7.5 u have a bit more ground clearance which is very helpfull in a 2wd truck, if it was a 4wd truck then of course id suggest a 8.8

but then again its just my personal preference, a rear axle in the mud doesnt see NEARLY the stress one would on the rocks, so i dont see the point of building something for overkill

 

Because there comes a time when you say... "hold my beer, watch this" and you are glad you went overkill

 

a welded/locked 7.5 will hold with 33's in any situation where u do that, i ran the truck for 2 years like that, went through front shafts like a *****, but never broke the back

 

For what it is worth, I have a 3.0L Flex with auto tranny, 8.8's and 4.10 open diff's. I am currently running 33X10.50 BFG Mud Terrains. While it performs ok around town and on the flats (@2,000 feet above sea level) I have lost approximately 2 mpg since moving from 255 75 R 16's to the 33 X 10.5's. I now average less than 15 mpg mixed driving (computed by a ScanGaugeII). It struggles at freeway speeds greater than 70+ and headwinds are bad news. I recently took the truck camping at 9,000 feet above sea level and could hardly maintain 30 mph in first on the mountain grades that I encountered. I am contemplating a regear to 4.56 or 4.88's and will likely go with the 4.88's.

 

Is the ScanGauge's calibrated for the tire/gear combo?

 

Yes, it was an 8% adjustment moving to the 33's. The speedo is now dead on with my hand held GPS and the fuel consumption is generally within a 10th of a gallon when I fill up. BTW, the fuel adjustment for my truck is roughly11.5% positive. Hitting the gas in any situation sucks as you see the instantanious mpg (or gpm in my case) drop into the 2-3 mpg range.