Hi Guys ! I got a old F-5 farm truck,wanting to make it a highway fun partime driver. Yep I want to keep the truck close to the original look.Has anyone ever swap rears,or ring and pinions in large trucks ?? I know I might have to have the axles and drums redrilled so I can keep using my 20 inch 5 lug budd rims.One guy offered to give me a IHC school large school bus 2 speed rear,but I dont know if it would help or how to check the gear ratio.If you have done this, what did you use ?? I know what your thinking why didn't I just get a 1/2 ton p.u. Well I like the looks of this big old original flat head stake bed truck. Besides I also own a 52 Mercury 1-ton and a 1940 Ford 1/2 ton p.u.,both converted to late model running gear. THANKS for any help you might offer. :-X11

 

I may be wrong but I think you will have a hard time finding any direct swap with highway gears.

On top of that anything too low and you wont be able to get the truck rolling without lugging.

Have you considered a Dana 60 F-350 dually rear? Wheel Vintiques and others can build you 20" wheels to fit the late 8 lug pattern.

 

Does your F5 have a 2speed rear already? If not go find one under a F6 to swap in. You'll probably want the vac assembly to with it. My F6 does 55 pretty easy on the highway. Anything over 60 is a screamer with the 239. I know there were two gear ratios for those 2speed axles, but haven't checked mine to see if I can go for a slightly higher top end speed.

I would think most of the modern axles are too wide. Seems like these bonus builts are all narrower than today's trucks.

 

the single speed rears would have been 5.14 or 5.83 or 6.67.
the two speed rears would have been 5.83/8.11 or 6.33/8.11.
i have a 51 F6 flatbed. the rear is 5.83/8.11.i never use the low
end. i also have a brownie aux gearbox in the middle. the brownie gives me 28% overdrive. i can go down a level road at 73 mph.
my engine is the big six flathead so it has better torque than the 239. the easy way is to find a rear from an F4 at 5.14.
if you go much higher than the 5.14 the 239 won't have the power to turn it with the 20" tires. i found this the hard way tcw

 

Hey TryMe,
Was wondering what you ever did with this rear swap?

I just got a 1950 F5. I am going to transplant a 351W and C6, but want to update the rear also.

I really like the idea about having new 20" steel wheels made and drilled to fit a late model 8 lug.....thanks!!!!

Always open for ideas!!!

Thanks, Mark