1970 Ford F250 Highboy questions

[Fordfan1971]

Hey Everyone,

Haven't posted in a while, but I recently got a 70 F250 highboy Single cab LWB 4x4. I would like to put a 390 in it with a C6. Maybe eventually go to a 3.9 4cyl Cummins later on (just a thought).

My question is: I have 390 and a 2WD FE C6 setup already, but can this be put in the truck and have a divorced NP205 behind it? Or do I just go snag a full 4WD setup from another truck in the junkyard?...

Also, i would like to put disc brakes on the front and Ive heard rumors of people saying the front axles from a 73-79 f250/350 can fit. Is this a direct swap?...

Thanks guys,

[eggman918]

The axle is a direct swap,when I did the 4bt swap I used a M5 then upgraded to a ZF transmissions both 2WD so I "think" that 2WD C6 should work as well.

[1972hiboy]

I purchased a 70 f250 4x4 a couple years ago for parts but the previous owner installed a c6 behind a 390 and is using a divorced 205 so yes it can be done. not sure about the intermediate driveshaft from the trans to the t-case. may have to make something.

[eggman918]

I would count on needing a different length intermediate shaft,also the C6 has a slip yoke.I would plan on $300.00 for a new shaft,but you might find a good used shaft that you could shorten to fit that would cost ~half of a new one.

[popeyes71]

Highboy bumps that came with an automatic C6 have a special tail housing that allows you to mount the gear selector for the transfer case. So you may need to locate the tail housing or a C6 from a 4x4 Bump. With that different tail housing, I'm not sure if that changes the output shaft length?

[hazelnut]

Highboy bumps that came with an automatic C6 have a special tail housing that allows you to mount the gear selector for the transfer case. So you may need to locate the tail housing or a C6 from a 4x4 Bump. With that different tail housing, I'm not sure if that changes the output shaft length?

67-72 highboy's come from the factory with automatics ? I didn't think the auto was a option in a highboy until 73.

[1972hiboy]

Highboy bumps that came with an automatic C6 have a special tail housing that allows you to mount the gear selector for the transfer case. So you may need to locate the tail housing or a C6 from a 4x4 Bump. With that different tail housing, I'm not sure if that changes the output shaft length?

67-72 highboy's come from the factory with automatics ? I didn't think the auto was a option in a highboy until 73.

Im pretty sure you could special order one with a c6. Not alot of them out there but I have seen a couple that people swore up and down thats the way it was when their grandfather got the truck.

[Fordfan1971]

Thanks for the info everyone. Glad to know it can work with some modifications so Ill start getting the parts together and see what I can do for mounting. As for the front axle, Ill try and grab one out of the junkyard from a 4x4 f250 dentside with disc brakes.

[hazelnut]

Highboy bumps that came with an automatic C6 have a special tail housing that allows you to mount the gear selector for the transfer case. So you may need to locate the tail housing or a C6 from a 4x4 Bump. With that different tail housing, I'm not sure if that changes the output shaft length?

67-72 highboy's come from the factory with automatics ? I didn't think the auto was a option in a highboy until 73.

Im pretty sure you could special order one with a c6. Not alot of them out there but I have seen a couple that people swore up and down thats the way it was when their grandfather got the truck.

I think I remember reading something on site saying it was a option for 6s. I'd like to find a highboy auto in the junk yard to take the transfer case shift mount from