i have a 95 f250 4x4 with a speed and 351 the problem i have is i believe it has 3:55 gears in it. its got plenty of power and will run 100mph down the highway with no problem but the minute i hook up to a trailer it dont pull worth a damn. wat i need to know is how hard and how much time will it take to replace the front and rear end ring and pinion i need to put 4:10s in it so it will pull. i have had plenty of other trucks with 351s but every one has had 4:10s and pulled good i pull a goose neck flat bed and gooseneck stock trailer. i pulled a buddy of mines 1 ton dodge last week and every little hill i hit i slowed way down i had to hit 4th and every now and then had to hit 3rd. i gotta have more power than this

 

Stop at some local garages and ask if they can do gear swaps, and how much it will cost.

 

That doesn't sound like 3.55's. My truck with a 302 has them and the thing could pull ten foot stumps. On the door jamb should be a sticker with your vin, trans code, and axle code. If you can put the last two up, it'd be helpful. I could at least tell you if you had 3.55's, the only axle code I know, haha