Just picked up a '55 F250 w/6 cyl and 4 on the floor... a real stump puller... more a tractor the way it's geared. The 6 runs great, but stop speed is 45 mph. I know 1st is always gonna be for pulling a stump, but at idle you can let the clutch out in 2nd without concern of killing the engine. My question is... am I looking at a trans change or ring and pinion? I would think someone has changes out one or the other before I got it. Is there more than one 4 sp. trans for this truck?

 

Change the whole rear end out. Are you planning on keeping the stock front drums? You can find a newer rear end depending on whether you want to stay with 8 lugs or go to a 5 lug explorer rear end and disc fronts.

I assume you still have the Timkem split rear end? I am not aware of any ring/pinion options to help with gearing.

I always swap out to either a Dana 44 (original to the F100) or Explorer rear end. Then I swap in a CPP front disc conversion to match the 5 lug pattern.

 

Inside the glovebox door you should find a data tag with build info for your truck, including the rear gear ratio. In an F250 it's probably 4.88, which would explain the ability to drop the clutch at idle. That's the way it was designed so as to not wear heavily on the drivetrain when pulling a load.

Options for higher speed driving would be to add an overdrive transmission or change the rear axle to more highway type gearing, like a Dana 60 with 3.54's.

 

Thanks, you nailed it. Gears are 4.88

 

Get a Dana 60 from a 1972 or earlier F-250. Install either a 3.73 or 4.10 ring and pinion and go. You may have to swap carriers but they are cheap used. Should be close to a bolt in swap with maybe a drive shaft length change. No brake system changes to worry about, use the drums that come with the axle.

 

I got lucky... she doesn't have the Timkem and when the weather improves I'll slip under her and find out which Dana it is. Once I pull the gears I'll find out if it's the original 4.88 or lower. Going to keep her as close to original as I can since she seems to be all there now, including the original 6 cyl engine and trans, so will research if I want to go with a 4.10 or drop into the upper 3's. Thanks everyone!