drivetrain for towing

[1971ford]

The '69 needs to be able to tow my '71 f250 race truck on a trailer back from desert races, down and possibly up the mountains. The '69 is also going to be my DD so i'd like the towing mods to not interfere too much with the 69's power (gearing would restrict me if i gear it for towing).
The tranny is a c6, I might throw in a manual valve body/shift kit. I'm also even thinking about going manual... but i think i'd rather stick with auto being that it's my DD.

What gears do you recommend that will be good for towing and still remain some go-fast speed? My rearend is a 9in.. Maybe i can have two 3rd members with different gearings. hmm. I'd rather not but it's possible.
I think i will be running 31" tires.

[FLATBEDFORD]

I'd say no taller than 3.55. For that weight 4.10 would be best.

[cdeal28078]

The ideal drive train for towing and dailey driver would include an overdrive. If you go manual go with the ZF 5 speed. It has a granny 1st gear for getting a load started and a 5th gear over drive.
If sticking with the c6 and 31" tires I would guess a 3.50 gear would work pretty well. I run 31"s on my 71 F100 with a mostly stock low compression 460 with a 3.25 gear and pulling a truck on a trailer locally isn't a problem. For the mountains and such I would think the 3.50 or maybe even 3.73's would be better. The 3.73's will not make for a very good daily driver in my opinion though. Interstates would be hard on it
clint

[1971ford]

alrighty. Thanks for the info.
I have another 9inch i got for free that has 2.70's, but i guess that wouldn't do me any good.

[cdeal28078]

What size engine will the tower have and what mods if any? A 2.70 would be a nice highway gear but I wouldn't want to pull much behind it unless I had one heck of a torque producing engine in front of it. I do like to run a 3.0 in my F100 but I don't pull much. A 2 horse trailer once every couple of years and maybe a truck on a trailer once a year or two. I have a 3.25 in it now but mainly because I don't feel like pulling it, swapping out the Lock Rite from it to the 3.0 and re-installing it. When I get peppy one day I will do that

clint

[1971ford]

The '69 will be towing it with a 390. I have another thread in the engine section for building the 390 to be a tower.
Im going to start looking out for 3rd members or just gears on craigslist.

[Redcap]

If you plan on towing very much with it, you might as well go 8-lug from the start.  Get a 4.10 geared D60 for the rear.

[1971ford]

I actually thought about that.
Swapping a D60 right into the rear and a front end off a F-250. hmmm.

[Redcap]

I actually thought about that.
Swapping a D60 right into the rear and a front end off a F-250. hmmm.

It would make for a hell of a lot better tow-rig than a F100.  Might want to find a F250 frame too, they are made of thicker material.

[1971ford]

I actually thought about that.
Swapping a D60 right into the rear and a front end off a F-250. hmmm.

It would make for a hell of a lot better tow-rig than a F100.  Might want to find a F250 frame too, they are made of thicker material.

going to a thicker frame would be a little too much.
But, that would be an awfully good excuse to go 4x4 like i've always dreamed of
Not now though..


I just got a good idea...
I've been wanting to convert my '71 offroad racer to 5 lug for several reasons. And my 69 would be better with more lugs for towing... Swapping the two would make perfect sense.
And for the rear, I want a 9-inch for the '71 (and it would conert it to 5 lug like i want) and i could use it's d60 (which has 3.73's) in the '69.
And... i will be swapping the '71 f250 leaf's out for better leaf packs soon, i could throw the f-250 leaves into the '69 while im at it.
There are a few little problems, like i have already welded the spider gears in the d60 together but i think that's about it.
So the only thing that a f-250 would have on my '69 f100 would be a thicker frame. Just how serious do you think it is that the f100 frame is slightly thinner? Do you think it would actually have potential of bending by towing a trailer? Iknow, they made them thicker for a reason, but just thinkin'. Is it more because the transferred weight on the tow hitch to the frame where it mounts? What if i boxed the frame in behind the axle and back?
I'm going to give this some serious thought!

[bawstenbilly]

You could buy my 70 3/4 ton Ranger with power steering c-6 auto with 4:10 gears

[1971ford]

I would i i had money and room for it

[Wes]

Your F100 is by far more than a capable tow vehicle, many newer trucks esp late 70's through the 80's. If you upgrade the axles and springs even better still. I would not be concerned about your frame, for towing any Ball hitch highway legal load.
  You can get new pinion idler gears and pin for the d60, no need to replace he whole third member.

[1971ford]

thanks, that's what i figured.
A F250 4x4 (highboy) chassis would be better for towing than my 2wd f100 chassis right?
I can see the highboy having quite a bit more weight (front end, t-case), and a few less mpg's.
The reason i ask is I am thinking that i will keep the f100 suspension, then once i come across a highboy chassis for a good price i will restore the whole chassis and put my body on it.
Having 4x4 sure would be nice for towing the trailer on the course when the '71 breaks, and for much more uses.

[Fordnatic]

You can tow an awful lot with an F100.  Make sure to use a good tranny cooler for that C6.