What should a bone stock 08, 2wd, reg cab, LB,3.55 rear axle run 0-60 in. Also, I had my 3.92 rear axle changed to the 3.55 in hopes of better mileage. I'm not sure I did myself a favor. Any help?

i dunno about a reg cab with those gears, but i got a qc and it ran about 8.5 stock with 392's

Dude,
3.55 is a highway gear so, if you do a lot of highway driving then you will see an increase in your MPG. For town driving the 3.55 isn't very good. I went from 3.55 to 4.10 and dropped maybe 2 MPG. Town driving is much better though.
I have an '03 4X4 RC/LB.

... and

quote:

What should a bone stock 08, 2wd, reg cab, LB,3.55 rear axle run 0-60 in

around 7secs or so.. with 3.92s, it would be slightly less.

I would guess about 7.2ish. Sounds like you have the same set up I have. I never used a stop watch though. The best I ever did with my superchip was 6.6 after full exhuast and a SC. before the exhaust I was doing 7.0. You should have kept the 3.92s haha

Do you have a limited slip? If not then it will be slower. I can't hook up With a posi. I can't imagine not having one.

http://www.060calculator.com/

with 5300 lbs and 345 hp at the flywheel it comes out to almost 7 flat. Close but that doesn't take gears into account which makes a big difference I would assume.