I have a 1948 Ford F3 and am either going to go with a 226 flat 6 or a 223 6 cylinder. I am wanting an overdrive transmission as it still has the original rear end with 4.86 gears. What would be a good OD tranny to put in it so I can get better Highway speeds but still use the power if I need to pull something.
Not a lot of easy options if you are serious about towing. The S10 T5 can be adapted to the flat six, not sure about the 223. But they are fairly light duty...
^^^^ Yes, a friend put an 86 O.D. into his 53 F 100, behind a flathead V8. Much better on the highway.
Ford, and a lot of others, used T86 & T85 Borg Warners with OD. the T85 has an R11 OD unit and they are very strong. Ford used them in pickups from '65 to at least '71. BW ODs are a bit quirky to learn but a kick to drive.
I’ve had the T86/od, the T85/od, the T-5, and one of the 80’s Ford 4 speed o/do’s. Watch the first gear ratios. Some I had are as low as 3.27 in first. With a 4.86 rear they’re useless without a big load. Some o/d’s are only .8, so not much help on the highway when light. With a 6 and not knowing the towing load it’s hard to say. But look hard at the T-86 R-10. I don’t think the six will hurt it if you’re sane, and the ratios will probably better. The T-85 R11 is stronger, but the ratios are pretty much the same. Just more money and harder to find.
The T-85 is definitely a stronger transmission than the T-86 but…….the T-86 isn’t bad. I consider it a medium duty transmission. Lots more parts are available for it too. Good luck finding any new gears for the T-85 type. Having said all that, I’m not sure I’d feel comfortable relying on the T-86 if you’d like to do some towing, hauling a heavy load, or a few hard runs down the quarter mile. If cruising the highway at lower rpm’s is a higher priority, with good gear ratios, I’d recommend the T-86. Remember that these are both side shifted transmissions that would be connected to steering column shifters, unless you can find one of the old Hurst shifters made for the overdrive transmissions. The regular Hurst kits can be modified to work with different shifter rods and a change to the mounting bracket.
Just out of curiosity, why a 223? If you have one in the garage already, I get it, nothing beats free. But honestly, what a gutless motor. If you want to stay with a 6, why not upgrade to a 300. It is the same bellhousing pattern as the Windsor V8 (289, 302, 351W) and which means many, many more bolt on Overdrive options. Plus you will have the added benefit of a bunch of extra torque and horsepower which will help pull things much easier.
In the fall of 1957 my dad, brother, and I towed a big grain dryer from Chrystal Lake, IL to Happy Texas to the grain elevator where Dad ran a shop. We used the company '54 F100 with a six. It went as fast as we wanted to go with snow, ice, & and poorly balanced single axle tow setup. No doubt the 300 is much more powerful and the last ones were injected. My son blew a couple if T86s behind his supercharged 289 Stude V8. One in low spinning the rear tires on our dirt road and suddenly finding some traction. The second one just could not handle the torque in second gear at high rpm + boost. It went just before he was ready to shift into 3rd. The T86 is a side shift but a top load. They also are non-synchro in first. I am putting one in my roadster. It is getting a top shift from a Jeep T96 with a little shift fork work. The hardest part to find is a 12v solenoid for the OD. Some of the newer OD trannys might be easier to find & use.
All of the transmissions mentioned so far would be considered very light-duty in a 1T truck application. To the best of my knowledge, none were ever offered for a truck application beyond 1/2T. Two-speed rear axles start showing up in OEM applications once you get into the higher tonnages back in those days. If budget is important, the Ford top-loader-based 3+1 OD with the cast iron case would probably be the best choice IMO in terms of buy-in and rebuild costs, durability, and ease of installation, but ratio choices aren't the best, and would still be skimpy with higher loads. You might look at the '87-up ZF S5-42 five speed Ford offered in trucks. Specifically designed for 3/4 and 1T truck applications (look for them in F250/F350 trucks), it's basically a three-speed trans in 2-4 but has a granny low for grunt and 5th gear is OD. Degree of difficulty connecting it to your early motor will have to be determined, but I suspect an adaptor will be needed. Ford also used a Mazda-supplied 5-speed in the F150 only, but those have proved to be not as durable.
Depending on the end use of the truck, it might be way easier to swap the rear end for a later F-250 (DANA 60) unit with say a 3:73 ratio. They are basically the same dimension up to '72.
There is no free lunch with this one. With the stock flathead six, bellhousing and hogs head you are going to have to have and adapter plate to hook any over drive transmission up. One option might be to go with one of Cornhusker's adapters that replaces the hogs head and has a Chev bolt pattern and run a later Chevy full size 5 speed overdrive. That would probably call for a custom pilot bushing and having the hole in the bellhousing machined out to fit the later trans's bearing retainer. I've never seen an adapter plate for a Ford F series Hogshead that a later Ford trans bolt pattern will bolt to to bolt one of the Ford pickup floor shift od transmission to the flathead. That doesn't mean that they don't exist and maybe some measuring of the input shaft lengths may allow one to use the Cornhusker adapter by doing a bit of machine work including drilling new mounting holes, remembering that 50 years ago they were drilling Ford bolt patterns on Chevy bellhousings to bolt a Chevy engine and bellhousing to a Ford trans. I'm not sure with the later ohv six as what fits what on post flathead Fords all too often is a case of you can't get there from here because __________ is different and you can't fit one to the other.
When it comes to vintage vehicles, going faster isn't the problem, it's keeping it in your lane and safely stopping. If your plan is to carry a load while blasting down the nations highways the only rational solution is to swap your cab onto a late-model frame.
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