Hoping someone can help out an FNG: Looking for some ideas on transmission selection for my coupe. I ditched the 350/350 combo for a 390 Caddy and want to go with a manual transmission. 390- '30 Coupe Tires- Radir cheaters, 29" tall x 9" wide Rear- 55 Chevy If anyone can give me an idea and what the particular transmissions come out of would be greatly appreciated!! Thanx
Thanx for the info so far. Looking for probably 4 or 5 not sure. Will probably be mostly around town but do plan on making some trips in it when done.
If you don't have one and have to spend money anyway, don't settle for less than a good one. Spend your money once, go with a good five speed. A T 500 should be enough for that engine, it has great ratios, and six places to choose for a shifter location. Use the correct oil in it and it will last you a lifetime.
took me a minute to figure that one out too . . . I believe they are referring to the tremec TKO-500/600s . . . Didn't come in anything out of the junkyard if thats what you are looking for. The only modern "decent" 5 speed that you can actually find in a junkyard will be the T-5. Fords had a shifter location almost on top of the output shaft and chevys up a little further. The problem with them is the case is super weak and flexes easily once you start getting out past 300ft-lbs or so. You can break one powershifting a stock mustang, typically into 3rd. Even if you don't beat on it, I've seen them break at 350rwtq+ in cars the guys didn't drive hard at all. 3550s (essentially the TKO case and later became the TKO 500 with a different spline input shaft) never came stock in anything, maybe the 95 Cobra R? doubt thats going to be in a junkyard. You *might* be able to get a T-56 from a scrap yard which is the 6 speed in the high end late model american v8s . . . camaros/corvettes/cobras/vipers. Your best bet is probably finding a rebuilt TKO on fleabay to hold the torque of your 390 unless you stick with the 60s 4 speeds.
With a 55 Chevy rearend which isn't particularly strong, I would not think you need a transmission that was too beefy. How about just a standard Saginaw 4 speed? They were put in a lot of GM cars over the years and if you don't race it, it should hold up fine.
There's also that gig where you take a Saginaw 4spd, a Saginaw 3spd with O/D, mix the parts up and end up with a 4spd and "mechanical" O/D. I have that planned for one of mine. Saginaws are cast iron 3 n 4spds that came in millions of GM cars. More than stout enough for a 390 Cad. I've had several 390s under my right foot and it won't hurt it in a light car like that.
I'd have to go along with what theHighlander said on both the Wilcap adapter and Saginaw trans of choice. With a good shifter you would have a pretty much trouble free setup unless you just hammered the hell out of it. I'm thinking that a T-56 setup would take extra work/pieces along with the the fairly spendy in comparison asking price. Sure would be fun to row that coupe though that many gears though.
So what's the word on these Saginaws? What vehicles did these come out of and they are a manual 4 speed? I remember seeing one for sale recently just don't remember where. I do plan on putting my foot in it every now and then but won't be an every day thing. Appreciate all the info! I'll have start researching a little more as well.
Not really sure what the difference is between the Saginaw and the Muncie. I'll have to do a little reading.
3550's came in late model Mustangs = '01 Cobras and later '05 - '09 V8's. They're tough but shift like a fn truck.
Highlander, tell us more. I am looking for a trans with an od, not real enthusiastic about the big spread in the 2.95 first gear T-5s, would like something closer ratio in the first 4. I will be running a mid-four final drive with a buzzy 300" overhead , the T-5 ratio spread is gonna suck The saginaw would probably survive with a typical period-correct 7.50x15 contact patch.
I did, still WAAAAY too big a spread. I am looking for something more like a close ratio t-10/muncie type 2.20/1.60ish spread. the 2.54 low saginaw is at least in the ballpark...
go with a mid 70's t10 borgwarner 4 speed , reasonable price and still a lot of them around, my .02 cents
Well, we are wandering way off the theme here, but a Super t-10 is stronger than a muncie, and a muncie is stronger than a t-10.
falcongeorge, the 4spd O/D gig is listed here and on some early Chev PU sites: http://www.jalopyjournal.com/forum/showthread.php?t=647821 http://www.chevytrucks.org/tech/overdrive.htm I had 1st heard of this on stovebolt.com or 348-409.com and think it's a great idea when you want to remain faithful to a build. It "seems" easy enough. There's the old pitfalls too like making sure your parking brake works or that the O/D unit is disengaged when parking on a grade. Some, being planetary driven, will free wheel backwards if engaged, even in gear.
most 390 cad do not have provision for a pilot bushing. you have to machine the crank or go with an adapter. i got a bendtsen's with tko-600 came with every thing you need to mount the stick shift of your choice.
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