How do I figure out what gears I have?

There are no markings that I can see on my rear axle.....

Thanks!

 

What RPM are you turning at 60mph? 70mph?

Or you could lift the rear tire and count driveshaft revolutions....

Dave

 

But currently the truck is getting a new VP44, Fass 150, and DTT trans.

Keeping in mind I have 285's, what should I be running at 60, 70.

 

check your glove box. mine is written on a sticker on the inside of the glovebox

 

Call dealer with Vin number

 

Glove box and inside the driver's door also if I recall correctly

 

What're the benefit of 410's vs 355?

 

4.10s have more grunt to the wheels. They will pull a trailer through the hills with less downshifting (if not bombed) or lower EGT (if bombed).

They also seem to have more options for aftermarket traction enhancement (lockers, LSDs, etc).

The difference between them is about 300rpm at highway speeds. Or, for the same RPM, you'll be going slower. For example, with 3.54s, you'll be doing ~71mph at 2K rpm. With the 4.10s, you'll be going only ~62mph.

 

I believe that it says on the sticker under the hood also, look up at the latch with the hood open.

3.54 = better mileage
4.10= more power worse mileage.

 

check in the engine bay under the hood i believe along one of the sides ontop of the fender, mine is not on the glove box or the door, but under the hood says im running 3.55