My '40 Ford Coupe should be in my possession within the next 2 days. I have on the engine stand an 8BA block I will be building up for this. I want to build this up for driveability as far as the engine goes. With that I have been thinking quite a bit about the transmission. As of right now I am planing on going the T-5 route, but is it possible to run a T-56? I plan on using this thing more than once a week on the one way 20+ mile drive to work, at 60-70mph. I also intend on hitting up some of the SoCal shows and some long range highway runs with it too. How different are the 2 transmissions for this type of driving? Is the T-56 even a viable option behind a mildly built 8BA? I guess the latter depends on gear ratio and tire size, but... Yeah I searched here and google, and didn't really find anything. I even looked for bolt pattern pics. The T-5 stuff is easy to find. Yeah this probably isn't all that HAMB friendly, but I figured this would be the best place to ask with so much Flathead Ford information/experience here.
Am I correct thinking the T-56 is a six speed? If so, I have to wonder what gain there could be vs a T-5. Is the overdrive ratio of 6th gear very different than 5 th in the T-5? I doubt it would be more than a few percent at most. So the primary difference (aside from significant cost) is the extra gear between first and top. For a primarily street driven "mild" flathead that would seem of little or no practical value no matter the cost, but when cost is factored in, it would seem to be in the negative column. That said, our cars are an expression of our personalities and if that's what you want, go for it.
Just run a t5. I got over 30 mpg with a nasty stroker flathead in my T Bucket with an S10 t5. Easy to do. Readily available. Do it.
This is the exact question I for some reason could not put into words, that is on my mind. Apparently there are several different gear ratio options, so if going the used route tracking down the most usefull one may not be worth the effort/cost. But I am in the idea/planning phase and want as much info as possible. Keep it coming!
The two biggest reasons are OD gear ratios and the strength of the t-56 vs the t-5. The t-5 od ratios are good, but not great, depending on the model you get, it could be .72 to .78, these are fairly common, there were some lower ones, but they are very difficult to find. Where as the t-56 od ratios are .50 or .62, both are a lot lower and would provide better highway driving. Unless you can find, and rebuild a WC t-5, the strength of the t-56 can not be beat, they were built for camaros, vettes, vipers etc, sure sounds a lot better than something meant for an s-10 or astro van. I am currently running a t-5, but it has been beefed up as much as possible, it's mated to an s-10 tailshaft to get the shifter located properly, and I'm running the camaro gear set, 2.95 first and a .63 od. I'm very happy with the performance and drivability of the trans behind my flathead, but if I was going to do it all over again from the start, I'd go with a t-56, and have less into it than I do in my t-5.
I would give Gene Benson a call at http://www.flat-o.com/carproducts/5speedflato.htm Gene not only makes these adapters but also had/has a transmission shop and can give you all the information you could ever want. Personally, a T-56 is nice, but totally overkill for a flathead motor, even a 300hp monster, and the issue with your little flatty is trying to use 6th.................unless you were going down hill with a 50/60mph tail wind having 6th gear is pretty much pointless..... The S-10 will work fine, and as far as being weak, well..................there are a ton of people using them without problems. IMHO
Are you planning on running the stock clutch/brake setup? That would make a difference as to what you are looking for (ie. do you want a full bell or a 1/2 bell) If stay with the stock setup and the 1/2 bell option, you could try to find the "hogshead" from the front of a later heavy duty 4 spd, you can find them in some of the '48 + bigger trucks. Using a 1" adapter plate you could have any trans bolt pattern added.This is common with the T5 but you could easily do the T-56 pattern as well.
Unless you're running better than 4.11 gears or really small tires, the OD issue is simply a matter of shopping for the right T5 for you. Unfortunately, there are a lot of folks who don't understand how to figure out which T5 is best for them... Or 5.0 Mustangs running 11s in the quarter? The T5, even the "fragile" NWC, 4.03 geared, S10 T5 is more than adequate for all but the most robust flathead.... You shopped around for yours & made a decision on the T5 that suits you. I'm glad you're happy with your T5 - not so sure I'd go through the headache of adapting the T56 to a flatty for little usability...6th gear? Not really usable for most street-driven flattys....
I've thought of the same thing, love those T-56s, and it's cool to do something different (in my opinion anyway). I came across a guy that had a T56 behind a flathead, I think it was an 8BA, and I think he went with the route that MN Falcon just explained, but I can't remember for sure. Here's some more chatter on the subject: http://www.jalopyjournal.com/forum/archive/index.php/t-134764.html
I think a T-56 is overkill for a flatty. My wife's roadster with an 8BA and a T-5 really drives great with a 3.00:1 axle and 26" tires. That thing will cruise all day at 70 mph, gets great gas milage and with the nice low gear and decent spread of ratios...it is fairly quick for a stock flathead motor.
Yep. Wilcap is the best way to go. I have a flatty with a wilcap adapter backed up to a 200r. Works cherry.
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