I am trying to get my 77f150 4x4 back on the road aiming for better gas mileage be able to travel speed limit.
These are the choices I am looking at;
Taking body off and putting on 90 frame, but have to change clutch to slave(is there a conversion kit)
putting 90 model running gears under 77 frame
Either way I will still have to change clutch to slave
All help greatly appreciated.

 

Another option is a 2011 or newer frame of the approximate wheelbase with either a 5 liter or ecoboost... much better fuel economy but will lose the stick. And the computers of course!

 

Will the newer AT fit up in the narrower frame of the77?

 

Not sure but that setup isn't a highboy so it will still be a wider frame at least under the cab

 

What is your setup now and how bad is your mileage? If its anything like mine, it isn't that good, 10mpgs is about as good as it gets for me, but I don't care - I like it original.