There is a 78 4x4 f250 frame locally for sale with no axles for $125. What I want to know is if I build this frame up can I put in a 390/np435/205 in it by changing the engine towers from a 77 or earlier? And if so would 2wd towers work? The ad says it was a 2 tank frame just in case that makes a difference.
Thanks for your input.

 

I can't answer all your questions but I'll tell you what I do know. 2wd trucks dont have engine towers, the engine mounts bolt to the crossmember which 4x4s dont have.
Yes you would need the towers from an FE 4x4 truck, and thats 76 or earlier. 76 was the last year for the FE's.