I have a 4wd 1955 F750 Big Job with a 317 in it. I use the truck a lot but it would be even better if I could get some more power out of it - I live at high altitude and climb steep hills. What engine is a good swap for the 317 without having to make too many modifications? Do any of them bolt up to my 5-speed tranny the same? The tranny is starting to lose a synchro so I may be interested in dropping in a motor/tranny combo but they would have to work with my divorced transfer case too.

 

This is up my alley, most here know im kind of partial to those 391's. I
suppose you could use a 330. Although I prefer a 391. Find one with
bell housing and this will go right in with no mods. Many were in cab overs
and if you find one with a high mount fan all the better. More common is
with out high mount fan, no problem just lower the fan shroud. Bellhousing
is direct fit with mounts, front mount also direct fit. All the 5speed Clarks
bolt right up. Exhaust also direct fit. No insult to Y Lincoln lovers, but
they are all noise and no go. 391 extremly quiet, smooth I got 4 trucks
the hardest part was a lifetime finding HD 5 sp Clarks with OD which I did
I can roll along at 65 hear a pin drop doing around 28-2900 rpm. Im not
a salesman but only if you come here and drive one you will be a believer.
Also 361HDs will work. If you are not familiar with differences with FE
& FT engines --you will be looking for exhaust manifolds dump in the
center the usual two thermotats heavy front damper with several pulleys
most have power steering pump (good for the future) lets see what else,
oh I used all the Y block senders so my gauges work as should. Please
click on my garage you will have to roam around to find a pic a 391 in
a 53 F900 Its in there although even I have to click around in there.
Guess Im lucky found all of these locally even with air compressor for
my brakes. samuel

 

Wow! That's great info! Is your OD built into the transmission or bolted on the back? I wonder if I have room between transmission & transfer case, it might make the drive shaft too short. My truck is geared pretty low and doesn't go very fast, OD for the highway would be great. I'll start keeping my eyes open for a 391. Thanks!

 

Answer ; the 5 speed direct and overdrive transmission dimentions are
the same, overdrive is acomplished with internal gearing. Upon searching
dont only look for Fords Clarks are used in many trucks even Military.
Mine came from an International. You really cant depend on numbers
on the case, I have only found painted codes or numbers, the only test is
5th (OD) the shift will be right and up pointed up to the ash tray, like
where reverse is.

 

Answer is both direct and OD casings and or dimentions are the same. OD
is accomplished with internal gearing. Dont only look for Fords, they were in
many trucks & military. Mine came from an International. The shift lever
in 5th OD will be pointing right and up to the ash tray next to reverse.
Like everything else, they are out there, just got to keep watch. sp

 

OK, eyes are open. Maybe I'll have a winter project...
Thanks.