Tremec 5-speed conversion for C2?

[Joe R.]

Hello All:

Please don't shoot me, but I am planning to install a Tremec 5-speed in my 67 this winter. I promise, no original parts will be harmed in this process, and the original transmission will be retained for possible future re-installation by me or a future owner.

With that said, I see that at least two different companies sell Tremec conversion kits for the C2. One is Keisler Automotive in Tennessee, and the other is Classic Motorsports in California.

Does anyone know how these two vendors compare? One thing that concerns me about the Tremec conversion is that the shifter has to be relocated to fit the C2 shifter opening. At Carlisle last year I looked at how Keisler accomplishes this, and it looked a little hokey to me. On the other hand, I think Classic Motorsports may have used the same approach, which may be unavoidable given the constraints.

In any event, I would appreciate hearing some feedback from anyone who has experience with either of these two vendors.

[Wayne P.]

Re: Tremec 5-speed conversion for C2?

I have two close friends that have done this conversion. Both were Keisler, I believe. The shifter works ok, once finally adjusted correctly. Anyway, one loves the conversion. The other hated it and put his muncie back in.

[Stuart F.]

Re: Tremec 5-speed conversion for C2?

Wayne;

The one that likes it - does he have a 4.11 Rear End? And the one that don't - Is he running a 3.36 or 3.08 Rear End?

Stu Fox

[Bob B.]

Re: Tremec 5-speed conversion for C2?

Joe,

I know a guy who also loves his Tremec 5-speed. However, I did something different. My 3.70 is now a 3.08 and my close-ratio 4-speed is now a wide to make up for first gear. I am running about 2,900 at 75 mph.

Bob

[Joe R.]

Re: Tremec 5-speed conversion for C2?

Hi Wayne:

Please tell me more about the guy who hated the Tremec and put the Muncie back in. What was it about the Tremec conversion that he did not like?

[Tom B.]

Re: Tremec 5-speed conversion for C2?

I have a close friend that has well over 100k miles on his Keisler Tremec conversion on a 383 in his '76. He is now in the process of freshening up the engine and tranny and putting it in his driver '68.

Also take a look at the Classic Chevy 5-Speeds engineered Corvette conversions. I have heard a lot af good about them too.

Tom

[Jean C.]

Re: Tremec 5-speed conversion for C2?

I haven't put a Tremec in my '64 (yet); however, I have driven Corvettes with the Tremec transmission and they were an absolute blast. One had plenty of power via a 502 crate engine and the other plain vanilla 327. Shifting is a dream in either car. I do not know what rear end ratio was used in either car. Both used the Keisler set-up.
Best regards

[John H.]

Re: Tremec 5-speed conversion for C2?

I wrote a step-by-step photo-illustrated tech article on a Keisler/Tremec TKO-500 5-speed installation in a midyear in the April '07 issue of "Corvette Enthusiast" magazine that you might find helpful.

[Joe R.]

Re: Tremec 5-speed conversion for C2?

I wrote a step-by-step photo-illustrated tech article on a Keisler/Tremec TKO-500 5-speed installation in a midyear in the April '07 issue of "Corvette Enthusiast" magazine that you might find helpful.

Hi John:

I am a loyal subscriber to Corvette Enthusiast, and I read your article when it came out (I always read your articles first when the new issue arrives). I'm convinced that the Tremec will fit without any permanent modifications to the car, and that is a big plus. So, the only questions that remain for me are:

1) Are there any "hidden" problems such as a noisey or balky shifter, given that the shifter location for the C2 requires a rather odd configuration on the Tremec? When I questioned Keisler last year at Carlisle, they told me that their initial shifter design had a noise probelm, but that has now been fixed. I have also heard conflicting reports about the Keisler shifter being "great" and "a bit stiff."

2) Are there any tangible differences among the three vendors, Keisler Automotive, Classic Motor Sprorts, and Classic Chevy 5-Speeds?


Right now I'm inclined to plunk down the money for a Kiesler kit this year at Carlisle, but I figured I should do my homework in advance to make sure there are no hidden surprises.

[Jimmy G.]

Re: Tremec 5-speed conversion for C2?

Classis Chevy is better in my opinion. I had issues with Keisler.

[Joe R.]

Re: Tremec 5-speed conversion for C2?

Classis Chevy is better in my opinion. I had issues with Keisler.

What sort of issues? Which vendor's kit did you end up installing?

[Wayne P.]

Re: Tremec 5-speed conversion for C2?

The guy that didn't like his and went back to muncie, never could get it as smooth as the muncie. Tried second drive shaft, second clutch, second transmission. Never smooth. Read that without vibration. Swapped back and smooth as silk.

[Duke W.]

Re: Tremec 5-speed conversion for C2?

I think you're better off with a Richmond Super T-10 wide ratio (2.64, 1.75, 1.31, 1.00:1) with a 3.36 or 3.08 axle. It's pretty close to a pure bolt-in and will probably be less expensive than a Tremec. The 3.08 yields about 2350 at 60 and 2600 with the 3.36, which is about 3100/3400 respectively at 80.

With the Special 300 HP cam and some compression, it would be a killer combination - near big block acceleration, 150+ MPH, and 20 MPG on the highway. Your heads have the flow!

Depends on the model, but most Tremecs have a stump puller first gear - much shorter than necessary - especially with a short axle ratio and have a HUUUUUUGE gap between fourth and fifth.

Comparing the "intergear ratios" of the Richmond and the WR Muncie is interesting:

Super T-10 1.51, 1.31, 1.34
Muncie WR 1.34, 1,28, 1.48

Note that the big gap on the Super T-10 is between first and second - the way a good transmission should be. You will hardly feel it, unlike the big 3-4 gap of the Muncie and even wider 4-5 gap on most Tremecs.

Send me an e-mail (NOT a PM) and I'll send you an Excel sheet that you can use to analyze any transmission, axle, tire combination. It computes all the intergear ratios and rev drops. You just input the ratios, tire revs/mile, and shift points.

Duke

[Bill M.]

Re: Tremec 5-speed conversion for C2?

Super T-10 1.51, 1.31, 1.34
Muncie WR 1.34, 1,28, 1.48

Note that the big gap on the Super T-10 is between first and second - the way a good transmission should be. You will hardly feel it, unlike the big 3-4 gap of the Muncie and even wider 4-5 gap on most Tremecs.

Duke

The only problem I've had with a big gap between 1st and 2nd is synchro durability. I drove a '59 T-10 close (1.3 gap) hard for years before I had to do the 2nd synchro. I had a WIDE ratio brand F (1.7 gap) and driving it hard trashed the 2nd synchro very quickly. Maybe the 1.51 is still OK?

[Duke W.]

Re: Tremec 5-speed conversion for C2?

Second gear synchros are usually the first to go for most drivers, and the cause is downshifting. The problem is non-existant to those who double clutch downshifts. If you develop the heel and toe technique you can easily downshift while braking.

I had my T-10 gone through by an experienced T-10 hand at 115K miles. It didn't need new synchros. It's a '63 340 HP/CR/3.08 axle, so I shifted down to first for many low speed corners - as high at 40-50 MPH during race track hot lapping events! I used the heel and toe downshift technique since new.

Phil Hill described it in Road & Track, so I knew it has to be the right thing to do!

Duke