Questions about mounting a 71 F150 on a 78 chassis

[Joshpow]

The rear cab bolts will not line up at all. The front cab mounts and radiator support bolts line up OK. I am unsure about the bed, but I don't think it lines up either. I would consider swapping the running gears, suspension, and front axle onto the 71 frame. That would be my advice. I am not 100% positive of this, but I am pretty sure I am right. Tats my , but if anyone else has positive advice, consider it over mine.

[mljjones67]

Everything from the cab forward will bolt right up. You might have to drill new holes for the rear cab mounts but there is a spot already there for the holes. The bed will not! Ford lengthened the frame and made it wider behind the cab. It can be done. You will have to make new hole in the bed in spots that don't have much support. You will also have to move the real axle forward I believe to center the rear wheels.
I am doing a similar swap. I am putting a 67 cab and front end on a 79 f-250 4x4 with cummins 6bt. But I will be putting a aluminum flat bed on the back. You can read through my build up thread in my sig.
Hope this helps