converting from 4:10 to 3:55

[qmlogan]

I am new to this site. I just drug a 96 out of field not running and am trying to put it back into shape. It is running now, but with the 4:10 gears the fuel mileage sucks. I also bought a 2001 e350 powerstroke cargo van with bad transmission. My question is will the 3:55 rear end out of the cargo van be able to be put into my 96 f350 truck? I have always been a cummins man so any input anyone could give me on any other ideas would be great. Thanks

[bigcountrysg]

I am not sure what axle is in the van. There for I can not say if the swap would work. How ever since your truck is 4wheel drive you would have to swap the front gears as well.

[rednekexprez]

messure spring purches,and ujoint sizes..I think they are the same...

[pipelayerjdh]

I'm not sure with the vans, but frame width on the OBS is 38" and on SD trucks 34". Vans also have different wheels from the trucks. The lug pattern is most likely different. I haven't worked on any vans, so I'm not 100% sure, but if it were a '01 truck rear, it would be way off and you would have to do some work to get it to fit.

[sldghamr]

i have 4:10's on my 96er and i can get 16 average MPG without much effort.

[qmlogan]

i am only getting 12 or 13 with the 4:10 gears. i bought a 95 f250 2wd for parts today with 3:55 gears. Is there anything special i need to do when swapping the rear ends? I don't want to do much to the truck. change gears, 4" exhaust, and air intake. Any other diy mods or secrets?

[pipelayerjdh]

Originally Posted by qmlogan

i am only getting 12 or 13 with the 4:10 gears. i bought a 95 f250 2wd for parts today with 3:55 gears. Is there anything special i need to do when swapping the rear ends? I don't want to do much to the truck. change gears, 4" exhaust, and air intake. Any other diy mods or secrets?

Go ahead and inspect the ring and pinion and change the lube. Check out the FPR shim link in my sig.

[craig long]

how do i find out what gears i have in my rear end? thank you.

[qmlogan]

there should be a metal tag on one of the bolts on the cover of the rear end. The tag should tell you or write down the numbers off the tag and call your local ford garage and they will tell you. i have heard from some guys that there is something you should do with the wastegate on these trucks. what should i do?

[craig long]

gmlogan, are you still looking into the wastegate delete?

thanks for the tag gear i.d. info!