I am in the process of getting the "Beast" (see my garage for pic) back on the road and I have a question. It is a 1974 F250 chassis 4x4, with a 428CJ, a 4 speed good old granny trans and I think a Dana 24 divorced transfer case. It has 40" Gumbo mudders on it now. The rear end is a Dana 70 out of a 75 F350 dually with 4.56 gears. I am planning on putting a coil sprung front end out of an 05 350 Super duty in it. This axle has 3.55 gears. Future plans include dual transfer cases and possibly larger tires. My question is which gearset should I change, the front or the rear? I know the wheel bolt patterns will be different and that I will have my work cut out for me adapting the front axle to the frame and steering, but the rig has an old Dana 44 closed knuckle front in it now and I have the Super duty front end laying in the back of my shop collecting dust.
I am looking for max power, not gas mileage. I would like to get this done before winter hits. Thanks. If anyone in my area wants to help, let me know.

 

Jeez...I'd think that with two transfer cases, the 3.55 gear should be OK. Hell, I'd think that if there was a taller gear available, you'd be safe with that!

Of course, if you go with the 4.56 gears and dual transfer cases, you could go enter "slow truck" contests.

I'm no expert, but with that kind of torque multiplication, a fairly high gear shouldn't be an issue. And I still haven't even started painting my truck yet, but I might be able to spare a few hours here and there if you'd like some assistance...all you gotta do is ask!

Later...
Pat

 

With the 40" tire I would go with the 4:56's for sure.

 

Stay with the 4.56's for sure with 40 inch tires.

 

might be able to go with 4.88's thats what i run in the one bronco withteh front 60 rear 70 and 42's

 

I am going to take the housing and one axle to my local spring shop to get straightened in a week or so. I decided to use 4.56 gears. I will need one radius arm from a 05 or newer F350. Two 73-79 F150 upper coil spring perches and a track bar of some kind to mount the axle. I also have a steering box out of a late 80s E350 ambulance that I think I can use to set up power steering. Camping season will be over soon so I figure to get into it the first of September.

 

the 4:56's sound good to me Beast. I have them in my 83, with the old 460, C3 and 38's there was no problem turning them or losing torque. Just uses a lot of gas. I have since put a 400 in it but haven't had it on the road yet. Yes I like torque.