I have a 1993 F-150 w 3.08 gear in it. I want to swap it for a 3.55.

What year models can I use? I want to swap the whole axle out.

 

any with the rear toner ring would suit.
Keep into account if you want a limited slip too.
These trucks with 3.55's are everywhere. should be easy to find.

 

OK i guess 87-96 will work. Wonder why they put the 3.08 in w the 4.9. Mine is manual and the book says towing is limited to 1900 lbs. With the 3.55 it is 3300lbs. That is a major difference.

Another question.

I am running 31X 10.5 X 15 and my brother paced me in his Lexus LS400. At 60 he was going 64.

When I change to a 3.55 will the difference increase to 8-10 mph off or get closer to being correct?

 

any 8.8 diff with the 3.55 from a 80-96 1/2 ton will work. i believe they all have the VSS in them, its simple to spot, if theres wires going to the diff it will work

the gear change WILL NOT alter your speedo in any way sape or form, however in the 92-96 trucks you can calibrate your speedo by yourself and its incdredibly easy.

the towing things are stupid ignore them haha. my 95 just towed my 92 home the 92 weighs in at 6050lbs plus probably another 1000lbs worth of trailer and stuff...and my overall ratio is roughly 3.55 with my gear/tire combination

my 95 had the 3.08s in it too, most of them did from factrory, its because the 4.9 is a very low revving engine and is most efficent below about 2200 rpm i believe. where as a v8 likes 3000 and up all day long.

 

It will be closer to correct.

 

the tone ring for the VSS is bolted between the carrier and the ring gear. the ring gear will only spin as fast as the tires. no gear ratio difference will change how fast the ring gear spins. the different ratio changes how fast the pinion is spinning in comparison to the crown gear therefor altering the RPM at any given speed. no matter what you do that ring gear speed will not change until you change tire size.

 

Your thinking too far into it bud. I agree with you on the fact that no gear change will make speedometer read any different. In the same token, no tire change will make the speedo read any different.
I was talking about the physical speed that the truck is moving. If you have bigger tires and drop your ring and pinion it will bring the speedo and the physical speed closer than 4 MPH off. It might even be a few MPH off in the other direction. Meaning instead of the speedo being 4 MPH slower than physical speed it might read 2 MPH faster than physical speed. But deff. won't be 8-10 MPH slower than physical speed.

 

On trucks with the rear axle mounted VSS only tire size affects the speedo, on earlier trucks with a transmssion mounted VSS both axle gearing and tires affect the speedo.

 

I stand corrected.

 

and a 93 will be axle mounted.

either way like i said the 92-96 speedos can be calibrated easily