Thread: C6 to 5 or 6 speed manual swap.

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The Nash rod I bought came with a C6 transmission. I would rather have a manual. It has a 351 Cleveland in it. Any ideas on what transmission would bolt up easily and give me 5 or 6 speeds with overdrive? It needs to be able to hold up to the power of the built up and bored over Cleveland, too.

Will a T5 bolt up directly to a 351 Cleveland?

Yeah the T-5 bellhousing will bolt directly up to the 351C. I'm not 100% sure how the input shaft does though. It may fall short to be too long. Not sure on that one. I'd assume it'd be the same as the 351C shares the same trannies as the 289/302/351W. Remember, it uses a cable style clutch setup too.
You'll "lunch" a stock T-5 when behind a Cleveland if you drive it any more than an old lady would. I haven't heard of the kit techinspector1 was talking about and I'll have to look into it for mine as well. A Tremec should survive with no problems behind your Cleveland though. The newer the T5 the better the torque load it will handle, as a general rule. T he over the counter Motoprsports T-5 is a pretty good unit but I think you'll need more than that. It's rated haigher than any of the other factory produced units.

Originally posted by Dano78
A Tremec should survive with no problems behind your Cleveland though.

What's a tremec? This is my first Ford anything, so I'm just feeling my way through this. I'm mainly a Chevy and Nash person. Thanks for any help, though.

Originally posted by techinspector1
Matthew, the Tremec is manufactured by TTC (Transmission Technologies Corporation), a joint venture of DESC and Dana Corporation. They supply light and medium duty transmissions to the OEM manufacturers and the aftermarket. 5-speed transmissions include the T45, T5, TR3450, TR3550, TR3650 and TR4050. The T56 is their 6-speed box.

Will the T56 work with my 351C? Were these transmissions put in any common production vehicles that I may find in a boneyard? Does the T56 have an overdrive gear?

The T56 has two overdrive ratios in most cases.

The Tremec is often preferred by the high torque crowd. It was originally designed as a truck trans, so is plenty stout, and a bit sluggish on shifts. If you're not trying to speed shift to the traps it shouldn't be an issue. This is a real popular trans with the Mustang, and Cobra replica crowd, even the big block boys. One advantage with the Tremec is that there are three different locations for the shifter, not only one as on the T5, so you can chose the one that suits the spacing of your car. The rear position, which is similar to the T5 is the standard. The other two are further forward and require a modification kit as the mount ups are different. So it costs a bit more to move the shifter, but the flexibility of locating is worth it.

Forte is the biggest dealer for these transmissions.

http://www.fortesparts.com/index.html

Originally posted by techinspector1
The T56 uses 5th and 6th as overdrives, with 4th gear as a 1.00:1 OEM applications include the Dodge Viper, Corvette Z06, SVT Mustang Cobra, Holden Commodore, Holden Monaro, Aston-Martin V12 Vanquish and Aston-Martin DB7 Vantage. There are actually 25 different part numbers for the T56. You should probably be prepared to take a second mortgage on the house to buy one. Get in touch with G-Force and ask about prices between their upgraded T5 and the T56.

If I found one of these cars at a boneyard, what are the chances of me getting a good transmission? About how much for a good one? Would one from any of these OEM applications fit a 351C or would I need some kind of different bell housing or something, and if so, where would I get it and for how much? I checked with Fortes and an offhand comment on one of their sub pages quoted around 2,000 but I haven't got an official reply back yet. But what you said about a second mortgage appears to be right. I may just have to live with what I have until I get out of college or become rich and infamous, whichever comes first.

Okay Matthew,
One more freebie, but then......................................

Checked ebay, TKO (rated up to 450#) $1375.00 + $100.00 shipping. Probably as good a price as out there, legally, for a new trans. Not sure, but you might have to get a bellhousing to make it work. Might be worth an email to find out. If it needs a housing and some other little gizmos (technical term, Richard can translate, he knows all that stuff) that may be where Forte comes up to $2k and be competitive. Pretty much typical pricing.

I have a 88 Notch with heads,intake ,blower,,I had a chiped burned and brought it up to Power Train Dynamics and had it tuned,with 10psi it made 492 to the rear wheels,I beat the hell out of it reguarly with the stock 80000mile T5 in it ,,i recently changed it out for a Motorsport version for the closer 1st to 2nd ratio,got it from summit for like 1100 hundred,, jim

Huh....that's interesting.... Never seen a T-5 take that beating. You must have a bastard T5 or something, either that or real low off-the-line rear wheel torque.

HTe Tremec TKO should be more than plenty for the Cleveland. I've never done the swap (to a Tremec) but word is the bellhousing is slightly different. Not so different that you couldn't take an earlier T5 bellhousing and modify it a bit. I think the two lower mounting holes for the tranny need to be filled and re-tapped in a slighty different location near the old ones. The pilot length may be the other concern. Hang aroung some 5.0 Forums and pick their brains, they'd have all the info you'd need for such a swap.

Hi Dan ,,,yea those stock parts amaze me,they take a beating,i have a motor sport clutch with 373s,,whats even more impressive then the trany is the motor is making that power with the original 80000mile short block,,,jim

Yeah the 5.0's are really impressive engines. I've heard for several 60k+ engines (even a handful at well over 100k) turning 10 second 1/4 mile times! Simply amazing. Hell I've got well over 225k out of my '87 351W in my '69 F100 and i tow and haul stuff everywhere.

I still can't believe your trans is taking those hard hits! I wish you many more mile outta that sucker and would be coll to see that combo run strong into the 100k club!