For highway drivability with a '49 Ford truck flathead, '39 Ford toploader trans, 3:78 geared banjo rearend. What would be better? 3:55 gear change and where would you get them? Or T-5 trans swap with existing rearend? Where would you purchase that? I should add this is for my '28 Ford roadster running 600.0 frt and 700.0 rear 16" rims and tires. Looking to make this more top end friendly, and am looking for pros and cons. Or what other options are there without breaking the bank. Thanks
If you run the t5 you'll have to go open driveline, and you'll probably have to cut up your frame to make it fit. The shifter gets moved too. I was in exactly the same position you are in. I've got 50 flathead with 50 trans and OD. Instead of cutting up my 41 truck, I went with the 50 motor with an open driveline 47 truck trans and 3:54 gears in the rear. Got the gear set from Speeway, but the pinon needed some machine work so that it would fit inside the banjo rear. Bought an open driveline kit from hot rod works. Had to get the driveline custom made. With 8.20x15 tires in the rear and the 3:54 gearing, I run 65 mph at 2500 rpm. The cheapest route to a few more rpms for you would be to just get the 3:54 kit, install it, and be done. The most complete solution, requiring more work and money, would be the t5 route. If you did this, then you may want something like 4:11 in the rear so that you can kill it off the line yet still have freeway rpms. Mike
I have about the same question,I am running a 51'merc engine & was wondering about running a F1 tranny,I also have the merc overdrive,I want the shifter in the floor,is there anyone who has mounted a floor shifter to the side of an overdrive tranny?I am running 354 gears in my banjo rear,I have an F1 tranny & was wondering just how much difference the overdrive had over the F1.Also do these early overdrives give many problems?
The quickest, cheapest, and easiest thing would just be to swap rear gears. Then either a t5 overdrive or an original ford overdrive would be nice. Both would require you to go to open drive. A 46-48 (other years too?) Truck rear is a banjo style open drive. This and the old overdrive would keep you in the '50's for sure. The early ford overdrive is a gear splitter, so it's a 3 speed, but with the overdrive being able to be used in any gear. Almost a 6 speed. I don't know if your typical 3 speed hurst floor shift is going to work on this overdrive, but it very well might. The t5 might give more installation problems. Might be easier to keep the floor shift. Definately easier to come by than the old ford o/d, and probably cheaper, easier to fix, and more reliable, but still not the same as the old ford piece if your hell bent on nostalgia. All in all you need to decide what's best for you. Do you want highway capabilites and town performance, or is just the highway drivability the main concern? Heck, if you really want to cruise you might want to change to an o/d AND the rear differential. Also, if you pull your 3:78 rear and put in an O/D and an open rear with 4:11 gears, you arn't going to gain anything on the highway, only around town performance. So if you go with OD and swap rears, watch what you swap in.
Thanks for the info, any kits out there where the pinion does'nt need modification to work? What exactly was needed to modify it? 3:54 gear change sounds like the way to go.
I got my 354 gears out of a 46-48' c-dan.Speedway has the open drive kit As does hotrodworks.The ford 46'-47'truck open parts fit the pinion on a taper with a keyway,& all of the closed pinions are splined so you can't use the truck parts with the car gears,The only gears they put in those trucks is 411,455.
Who has the best deal on 3:54 gears, also I don't think i'm going to change to a open driveshaft rearend. Advice appreciated, perhaps someone has a set they want to sell?
??? I think that if you check, 4.55 is 1942 4-cylinder only. 3.78 was standard, I believe, in 1942-47 open drive light duty trucks, with 3.54 & 4.11 optional. I have a 3.78 and a 3.54 (open drives). Mike
I have 5 46-47'rearends,& 4 of them are 4.11 one is a 4.55,I assumed that 3.54 only came in cars,I know that 3.78 is the most likely gear found in the banjo rears.I think ford put the 4.55 gears in the vehicles that were sold in the mountain country.Or you could order it.
Like Brush said, you can get a new ring an pinion with the 3:54 ratio for a few hundred bucks. With a buddy you can pull the rear out and swap gears in a weekend. just make sure you set the ring an pinion to mesh correctly. They might come with extra gaskets for shims and instructions on how to set them up.
Good Post! I have 3.78 ratio on my banjo, and a 4 speed manual M20 trans, what you think about running a quick change on the Highway??? That's a good way for fuel economy. Let me know if it's noisy? thanks
I got the 3:54 and Hot Rod Work's open driveline kit from speedway. If you go open driveline, I'd suggest buying (or making) the Hot Rod Work's torsion bar to strengthen the stock rear end setup that will now be missing the torque tube. So here's what I went through: 1. For me, the Speedway 3:54 pinion did not fit my stock 41 banjo rear pinion opening. 2. I had to get it machined. Other folks here and on Ford Barn have had the same problem with these kits. I even called Speedway when I first discovered this, and they said "Yep, we know about this, you gotta get it machined." Nice of them to tell you AFTER you buy it. The part is Asian, don't know if that has anything to do with it. Anyway, here's the machined part. Notice that just the tips of the teeth are turned down: 3. Here it is installed: 4. Here is the open driveline kit installed. I believe Cheaters Pete (or someone from Europe) posted a tech on making your own. I can't find it to link it. Hope that helps. Mike
This chart is pertinent to this conversation. I used it a lot when figuring out what tires to use and what rear end to build.
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