1970 Ford F600 Re-Power

Welcome aboard. I think you could take a rear axle from a semi, but a 2 cycle Detroit is where I'd draw the line. Maybe a 2 speed rear would work, but 2 cycle Detroits need to wind out, and a high ratio, the motor would not be happy. Besides, some states don't allow old Detroits, I think. I agree, a diesel is the way to go, and plenty of choices, depending on the power you need. Remember, a higher ratio ( lower number) may seem like the answer, but you have to make sure the motor can handle low rpms like that.

 

Lower gears like 4.10, 5.29 etc?

Tandem setup is fine, just use the rearmost axle. Voila! Single drive axle.

 

It depends what you want to do with the truck.

Ford was brilliant with the way they made those trucks because they were medium duty trucks that a lot of the F600 dump truck could haul 8 tons. They could do that because the gasoline engines were not that heavy and the Transmissions behind them we're not that heavy. And they were made to be light trucks that can pull the weight.

2 stroke Detroit's are very heavy engines. If you want to work the truck it's going to eat up the tonnage you can haul. Then you have to figure what transmission to put in and that's a whole other thing because if you put a road ranger in it's way heavier than was originally in there, and you're going to have to cut the firewall out to make it fit. To give an idea the original Ford engines were around 700 lb and the Transmissions were light maybe 200 lb or so. The lightest Detroit is probably like 1500 pounds at least and the road Rangers probably about seven hundred.

And because the diesel has a different Power Band than the gasoline engine you need higher gearing or you need an overdrive transmission but if you put a road ranger in with the six something rear-ends they have in them you're only going to do 40 miles an hour. I'm not aware of any rear ends that will fit that truck that are geared any higher.

And that is the next thing. I think that a regular semi truck rear is wider than what's on the f600. Same with the front axle. And it's also heavier so the same issues come into play with GVW.

Maybe you could put in an auxiliary transmission to give you overdrive but again that's more weight.

 

That model may have been available with a Cat 3208. I do know the '72 ford L7000 had them.i I forget gear ratio but one I drove had 2sp rear axle and 55mph was 2800rpm,,,never forget the racket that engine made...at -40 you could hear every stroke of the engine

 

I’ve seen early ‘70’s F600 cab’s installed on 1980’s-2000’s vintage F600-800 chassis. One Had from Ford 3.90 Rockwell rears, 11r22.5’s, air brakes, 6speed spicer and 5.9 Cummins.

An older Detroit would fit right in that chassis no problem. Chassis is the same dimensions as the big Louisvilles that became Sterlings. They just have a pickup truck cab on them. Set the cab up higher on it like an N series and an 855 Cummins would fit.

There were probably more 8v71 powered Louisvilles than any other engine in it’s run. Lots of trucking companys speced them like that.

Buy a complete salvaged cab and chassis and just swap the cab and front clip with the fabrication to go along with it. If you get a standard 260 inch wb 24-26 ft box truck chassis than you can cut it down to whatever custom length you want.

 

Eaton 10 speed will fit in just fine. You may need to bend the stick in a few places to get it to clear the dash or seats. And the bell housing is different size on some Detroits depending on what they were installed in. 8v’s and 12v’s worked really well with 13’s back in the day. The splits kept them wound up into the sweet spot. Just something to think about.

 

It would be an easier conversion with an actual air brake F800 truck.

Frame is heavier Springs are heavier axles are heavier and it would already be air brakes. And for all the extra heavy-dutyness of the F800 they don't weigh very much more.

The 12v 71 has got to weigh 3500 to 4000 pounds. Add a Road Ranger and you're probably approaching 5000 pounds. Some of the f600 only have a 7000 pound front axle some might only have a 6000 pound front axle.

Like I said the F800 is the better choice because it's much less to swap around and even if you keep that axle you're going to end up going through King Pins and things like that it's just better to start with the better project in my own opinion.

But sure you can do it. You can put it in a pickup truck if you wanted to.

In fact you could probably make a 12v 71 motorcycle if you wanted to.

 

F600-700 had airbrake option from Ford on the 26,000 gvw chassis too. Ryder and Penske had them to rent 20-25 years ago. Under cdl requirement as an added bonus.

There were a lot of hydro pump assist juice brakes on the roads back then as well that had the heavy spec 26,000 gvw axles. 3.90,4.10,4.33.

Not much faster then 3.90’s in the class 6 and 7 trucks because they all came with small engines. 230 hp and less and only 600 ft lbs. of torque output tops. Need the low gears to move and stay moving.