Im swapping my 3.08 gears to 3.73 with i feel a difference?
My 89 is a 5.0 headers dual exexhaust MSD ignition coil and E fan 3inch body life and 3 inch suspension

 

Holy crap.. yes I hope to tell you it'll make a difference, but if you got an AOD you should go straight to 4.56 gears.

 

Yes, you'll feel a difference, but you'd still be geared way too tall. I would definitely go with 4.56s.

My Bronco has a 5.0 with 31" tires, and I think the stock 3.55 gears are too tall. I'm going to re-gear mine to 4.10s. I couldn't imagine how bad 3.08s would be with 31s, let alone 3.08s with 35s.

 

I run a basic 35" all-terrain and run 4.88's. your super swampers are a heavy tire so take that into consideration as that will require more gear in my opinion to turn them with out taxing the engine and transmission. Also the AOD if im not mistaken has a taller OD gear and being that your 5.0 makes its power higher in the rpm than say a 351w being over geared wouldn't hurt .

 

I heard 3.73 would be good over all for highway street and a little mud, i have reused Mickey thompsons on it now
Im not sure what gears it has now, i looked online and found it has 3.08s

 

What do yall mean by AOD

 

That is a transmission.. what one does your truck have?

 

Not sure it auto idk if it has over drive

 

For a 302 powered truck with 35's? Hardly. Maybe if it had a 460.

 

What is the trans code on the calibration decal on the drivers door pillar? And while you're looking what is the axle code?

 

Will i be faster on the highway with the 3.73s or 4.10 or 4.56
My trucks in the shop

 

The bigger the number, the faster the engine will spin on the highway. So assuming you DON'T have overdrive, with 4.56s, the engine will spin at about 2800 rpm at 65 mph. With 3.73s, the engine will spin at about 2300 rpm at 65 mph.

If you DO have overdrive, the engine will spin at about 1650 rpm at 65 rpm with 3.73s, and at 2021 rpm with 4.56s.

Generally speaking, the faster the engine spins on the highway, the worse your gas mileage will be. But you don't want it spinning too slow either, because it won't have much power to accelerate on the highway and it will downshift a lot. I'd say 2200-2500 rpm is a good balance for a 5.0.

A bigger number gear ratio also means better acceleration around town. 4.56s will make the truck much faster from a stop than 3.73s.

 

At least 4.10, but depending on highway time and use of vehicle. I would think 4.56 would be perfect.