i would like to put a slightly more highway freindly transmission in my 1978 f-150 4x4 right now i have the 4 spd manual with the granny gear hooked to a 400v8 im thinking either a 5 spd out of a late 90's f-250 or 350 or if its at all possible a ZF S6-650 6 speed out of a super duty i had one in the f450 u used in a previous job and apart from the odd shift pattern loved it the fact that it has 5 highway gears and a crawler gear if this swap has been done before i would love to get intouch with the person who did it. or is it not a doable swap

 

Anything is doable. You will need a ZF 5 that was behind a 460 for it to bolt up to your 400. I don't think you'll be able to go with a ZF 6 because they never came behind a 460 or anything that will match the bell housing pattern of your 400.

You will also need to adapt a hydraulic clutch setup to your truck, or make the mechanical linkage work with the ZF, which I think is possible with the big block ZF's because they had an external slave cylinder unlike the small blocks which were internal.

 

so a 5 spd out of a mid 90's 250 would probly be a better option then i want to do somthing with the trans because right now its geared so low that it struggles to do 110km/h on the highway

 

a ZF6 isnt out of the question; You can have an adapter plate built for it. BUT, if your concern is your vehicle failing to do well on the freeway, have you considered just regearing your axles?


It's cheaper and easier than a transmission that was never meant to be there in the first place.

Not that "Easy," means much, but it's the easiest way to do what you mentioned.