ok first off i was never a ford guy till 2 years ago i bought an 88 bronco2 2.9 4x4 5 speed i was very impressed with this little truck i couldnt kill it it was great on gas push button 4x4 and my wife wouldnt drive it long story short i have decided to jump ship from a hard core chevy s10 builder to BB fords so i bought a bullnose f250 4x4 460 auto 3 speed the BB was rebuilt completely 3000 miles ago and what was a factory 225 horse power plant is now a 400 horse beast it has a dana 60 rearend that i broke two teeth off of by doin holeshots like im a teenager lol anyway i have never tackled a rearend job before but i know it has 4.10 gears my question is how hard is it to replace the 4.10's with a more fuel ef. 3.55 or even a higher gear? pics/diagrams/difficulty/cost/would be greatly appreciated thanx

 

remember the 4x4 part? lol just talking to the teenager part of you, you will need to replace both sets of gears front and rear

 

Find a 10.25" with the same gear ratio as what you've already got at the junkyard. You'll pick up floating axles and a ton of strength and have to work a little harder to break that one.

 

I broke a 10.25 with my 87 f250 with a 400hp 460 and factory 4spd.
Mine exploded with a no-lift shift into 2nd, drag racing an iroc z.
It was awesome...
Broke carrier, snapped pinion, bound up and broke 1 axle spline, and splooged half the mess out the rear cover.

But they are darn tough. The d60 with Detroit locker kept breaking both axles at same time. Now I have alloy shafts and it holds up fine.

 

thank you i will give it a shot

 

thanx for the reply i know i need to replace both but for a novice how hard is it to replace a ring and pinion gear and is that all i have to replace?

 

the gears have to be set up by someone that knows how to do it. gear mesh, backlash pinion bearing load, stuff like that.

 

thanx fdude64 i think ill let someone else put it back together

 

thank you aswell untamnd but its outa my league