how about the axle code on the door jamb? I think 3.55 is most common but there are a lot that came with 4.10

 

well, the tag was worth a try!!
on the rear door pillar is the trucks information sticker. give us the axle code and we can give you the gear ratio.

 

ok sory it has taken me so long to get back... the flu bug been kickin my ***....axle code is D5

 

D5 looks like a 4.10 limited slip.

 

cool...so what i have is a 10.25 diff with a 4.10 ratio..... i found 2 places to get a ring and pinion set for it, 3.55 is as low as they go though... better than the 4.10 for mileage

 

If you can afford a little more money, putting an OD would be best. Either an OD trans or a Gear Vendors add-on type. More money than the gear change, but then you still have the gears for potential towing. An OD would give more rpm reduction than the 4.10 to 3.55 swap.

 

i have an e4od tranny

 

I'd be doing the math to see how long it will take to get a return on your investment. Maybe someone who has done the swap can give you an idea of mpg difference. I know for the driving I do (rarely over 60mph) I would rather have 4.10's. That being said, I bought a used set of 4.10's for my dump truck from ebay ($50 or so). Sold the 3.55's for the same price, IIRC

 

Guess my brain thought you had an earlier non-OD trans, sorry for the confusion. Back to my sleeping while appearing to be awake.

Another thought is you could put larger diam tires and get a poor man's bump in gear ratio. Not all the benefit of 4.10 to 3.55 (13.4%), but you might get half that?

Cleaning up the aerodynamics can have benefit. Such as those large side mirrors exchange for smaller size. Get truck lower to ground and put an air dam to keep air from going under vehicle. Bed shell or bad top can help some small amount. It all adds up. Carrying excess weight does not help mileage either.

The benefits to lower rpms are more than just mpg, it also makes it quieter inside the cab, less wear on engine, runs cooler, etc.

 

my driving consists of making frequent emergency runs.....i drive fast

 

here its ready for you!!! this will help you drive fast!!!