Cost me $1900 to change from 3.73 to 4.30 gears on my 2004 F350. That was Ford OEM gears and Timken install kit (bearings races and seals)

also depending if you tow or not is go to 4.56 or even 4.88 gears...i didnt think ahead when i did the 4.30's, now that I'm adding a 4" lift and 35" tires I'm gonna have to regearagain this time to 4.88

 

What engine do you have by the way?

 

 

Did you like the truck stock? I couldn't stand my 5.4 stock with 3.73 gears, it was a total dog driving and especially towing and not even MAX weight either! Going to 4.30 gears makes it nice, the way Ford should have sold these gas powered trucks. So if you were fine with the truck while it was stock then 4.30 would be perfect for a factory feel setup, if you want a little better is go 4.56 gears. If you tow, off-road, or live in hilly or mountain terrain go 4.88 gears

 

I would get the 4.56 gears, and it would also be a good time to put a locker in the rear.

 

Cost me ~$2500 at my local Ford dealer with all new bearings and seals for front and rear axles. I went from 3.73 to 4.30.

 

I was quoted $1600 for front and rear 3.73 to 4.88 in my 01 F250

 

When we went to 4.30's from 3.73's we checked around to see what it would cost us to to have them installed. The best price we could get from a reputable shop was just over $2000.00. We ended up switching them out ourselves with some tutoring and oversight from a good friend who does that sort of thing for a living.

I would echo those who are advising you to go with 4.56's or 4.88's. If you do any towing at all go with the 4.88's. If you are going to run empty not towing I would go with the 4.56's. Our 4.30's are adequate since we are running the stock 31 1/2" tires but still there are times when I wish I'd have gone with the 4.88's. We tow heavy about 90% or our yearly mileage.

 

Another vote 4.56 gears with 35's, unless you run a lot of empty interstate miles. And if your doing that, my opinion is why would you drive a super duty? I'm geared 4.88 and 37's. It's great for the 55mph highways around here(that means 60-65mph).

 

Man this might be the way I have to go. Finding a 4.30 truck is impossible. I want 35's when I do get one, so 4.88s might get the nod.

 

I have a 4" lift for my truck for oh three years now sitting in my garage. Ever time i say ok this month i have the extra cabbage and im finally installing the lift something comes up, thsn im like dang oh well next month. I dont drive my f350 except for weeknds and NO MORE winters either so i might be ok with 35's and the 4.30 gears...but then i think to myself thats gonna get me stock setuo that had 3.73 hears and i absolutely hated the truck back then. So my point is think really hard about what setup to go with, you have the 5speed auto so going uo to 4.56 or even better 4.88 WILL NOT HURT your MPG and besides you drive a F250 its ot made for MPG anyways.
Also think about a detroit true trac or detroit locker...when i swapped from 3.73 to 4.30 i installed new clutches to the factory LS, four years later i toasted the LS clutches and said ok time for a locker. So 600 for a detroit locker and another timken masyer i stall kit and i was good to go plus some labor. If i would have thought it out better i coukd have saved around 400 dollars if i did the locker the first time. And now that i think about it i could have saved $2,400 if i did 4.88 and the locker the first time around!

 

 

No front and rear