If you only got to 31" tires 3.73s would be good, and you could easily upgrade to 33s with out much problem

 

i installed a tack today , 65 mph in 5th = 1900 rpms and 2300 in 4th with 308 gears .

 

Bass, I went to a 3.73. 95 2wd with aod. 30/9.50 tires. I'm very happy with them. I occasionly pull a 16 foot car trailer and neede more gear for it. 4.11's might be better with the 31's. The bigger tires will make the truck a little more unstable while towing though. Good Luck.

 

i think i am going to go with the 3.73 because of everyday driving .i am getting 17 to 20 mpg with the 3.08s what can i expect with the 3.73s. thanks for all the input ..

 

With 31" tires, and 3.73 gearing, 16-19 should be about right. While towing it should be alot better than with the 3.08s by about 3 mpg or so.

 

When I switched out I never really noticed a difference. The 30's really lgged the truck down in overdrive. Now it's gotten much more drivable.

 

3.73 and 33's??? Bad combo and far from good to go.

 

For towing I agree, but for a daily driver, city, that is a great combination.

 

I have 4.10s and a 460 with 32s. I drive mostly on the highway and it is just fine.

 

i think iam going to stick with the 235s maybe something more aggressive and wider.the truck is going in the shop this morning for the gear swap ill let ya know how in went in a few days .......

 

the truck is finished.What a difference its made i really love the 3.73s dont have to change gears much at all .can not wait to hook up to trailer i think it will do great .i was told to wait at least 200 miles before pulling .only 50 more to go........thanks for all the help..

 

I'm going to run 3.73s and 33's but I have a 300, so towing power/torque isn't a problem. It makes power so low that most of the gear calculators are not really accurate.

It could spin 33's on dry pavement with the old 3.55s before the wimpy 8.8 gave out

 

Why are you changing your gear set to bring the rpms up if it makes SO much torque down low? Hmmm....doesn't make a lot of sense now does it?

 

because 3.73s are a little easier on u-joints. they spin a bit faster but break less often, espessially with a new engine.

 

Oldhalftons,

I'll clarify why you need higher numerical gears. I used to have a 300 6 and they did have a good deal of torque for how many cubic inches they are. And they do make it down low which is really good. They also deliver great fuel efficiency and are about as dependable as a swiss watch. However, when you put large 33" inch plus tires (like I did with my 91 f150) on them they start bogg down because they don't have enough torque or horsepower, just like any other engine does (sorry the 300 six doesn't have magical powers). I had to swap for 410s after I went to 36s. I will certainly say it is better about this than some motors. However, If it were a 460 this wouldn't be an issue until you went into an even larger tire; perhaps a 38" or a 40" but it still happens even with all those cubes that have twice as much usable torque, and tripple the horsepower. However, they too are not immune to the large tire syndrome. They will need a change of gears because the overall gear ratio after figuring axle ratio and how it was changed with the bigger tires will make it have less mechanical advantage. They will be guttless as well and horrible to drive with big enough tires. You change the gears to compensate for the larger tires you put the engine back into its "happy" spot and then things go back to normal. Larger tires take more horsepower to drive due to the increase in friction, weight, and wind resistance. Because of this you have less power and less fuel economy. Depending on the extremes and how you drive it may not be that noticable, but none-the-less, it still does occur.