So Ive got a deal with some guy where im going to be getting a 97 f250 sterling 10.25 with 3.73 gears for free.

I currently have a 96 f150 the a 300 and 2.73 gears.

I'm going to get new tires and rims obviously for the new axle. Probably 33" tires. So my question is how is my truck going to handle the gear change?????? Highway rpm??? City??

 

What tires do you currently have with the 2.73

 

The last time that I figured it up on my 95 and swapping to 3.55's on my stock 235/75's, I was going to run about 400 rpm higher in 5th gear at 60mph. Running 3.73's and 33" tires, I'd guess you'll run around 600rpm higher at highway speed. 70-80 mph will be a strain I would guess. I'll pull out the final gear ratio calculator and see if I can figure it for you shortly.

 

I can't make this work on my smart phone! Anyway, here's a link to try.
http://www.onlineconversion.com/bigger_tires.htm

You need to know your current rpm at the speeds your curious about for comparison purposes. There are multiple calculators on this page which should tell you all that you need to know.

Using rough numbers, given a 1:1 gear ratio in 5th gear, you'll turn about 2700 rpm at 70mph. About 700rpm higher than I run with my 300 and stock tires with 2.73 gears.

 

The bigger tires bring the Rpms down I thought

 

They do, but not combined with 3.73's. Factor in rolling mass for the 8 lug spindles, drums, probably a heavier diff casing and 33" tires and the increased final drive ratio and it will add up to a stump puller that don't like the highway.

 

Yea thats pretty much what I figured, I don't do a lot of high way driving mostly smashing around back roads. So I figure my I might get better mileage or stay the same.
I pull loads up steep grades and the 2.73 don't like it at all. Plus I'm tired of getting the damn thing stuck in wet grass/mud due to it being a non LS.

Of I don't like the 8 lug I can always sell it and make money.

Thanks for all the help!

 

I was wishing I had limited slip last week when I got stuck. Lol. Wouldn't have helped with my nearly slick tires. I'm still going for broke at 115k miles on my rear tires.

 

So what are you doing with the front end?

 

Putting in 250 springs with the rotor, knuckle and dual piston breaks.

It's pretty much going to be a single cab short bed f250 haha.

I'm not sure if I have to change the master cyl tho.... But everything else should bolt up pretty easy.

I plan on going to a Dana 60 king pin eventually then I have money... But for now it's a 2 wheeler