KorbenDallas

My '81 already has a Centerforce Clutch with Chrome Scatter Shield,
so I want to keep that clutch. However, I would like a short-throw shifter. It also has a Muncie M21 close ratio tranny right now that I'm wanting to replace with a Tremec TKO 5-speed.

- I'm worried if the TKO would mate up properly with the centerforce clutch?

- The M21 had some fabrication done so the shifter would fit in the stock placement so it's actually a RX7 shifter. Would I expect similar mods when putting the TKO in?

- Any other fabrications that need to be done? Crossmember, speedo cabling, etc?

I'm not looking for detailed specifics right now, just things that I would need to think about while I'm saving for it. Also, I will have a mechanic do this for me, so answers to these questions will also help me find a good mechanic that knows what he/she is getting involved in.

Thanks!

Monty

I'm assuming you're using the Tremec TKO from Forte's. As long as your clutch is for a GM 26 spline tranny, it will work fine.

All you have to do for the shifter to fit the stock console plate opening is to space the shifter hamdle over about 2" from the shifter stub. I just use some long M8 bolts with aluminum spacer blocks I had made, or you could just use washers.

My car originally had a 700R4, and the stock driveshaft would ahve worked just fine, as long as I used some conversion u joints. I ended up having a larger driveshaft witht he larger 1350 ujoints amde anywya, since it relatively inexpensive and I wanted the strength and piece of mind from the large 1350 ujoints.

As for the crossomember, I just made an adapter plate out of aluminum plate. The TKo's rear mounts were about 3"-4" in fornt of the stock crossomembers mounts. I just cut a rectabular piiec about 5" ling and 3" wide, and bolted it in place. I am having a chassis shop modify my stock crossmember next week though. He's just going to make a new mount out of steel and weld it to the stock crossmember. That way the crossmember stays in the stock location and the e-brake cable doesn't have to be modified. The stock speedo cable will work.

KorbenDallas

Monty, thanks for the quick reply. I'm still saving, but in the future I might need your help before I order the tranny+parts. Off the top of your head, how much do you think this would cost me minus labor? I was planning on ordering form Forte's. Thanks!


[Modified by FroDaddy, 2:36 PM 11/11/2001]

Monty

Last time I checked, Forte's wanted about $2000 for a TKO. You can get the front yoke from him for about $225, or just have a driveshaft shop make you a new driveshaft with a new tranny slip yoke for about $250 or so.

You'll also need a shifter handle, which is less than $50 or so, unless you opt for a replacmement shifter altogether. If that's the case, up to $300, but make sure you get a shifter with a bolt on shifter handle, since you have to space it over.

Crossmember modifications shouldn't be more than about $100 or so in labor.

You could do it for $2500 plus labor, assuming your existing clutch is good.

81vette

I've also been thinking about this upgrade. In the process of looking under the car at the cross member, I noticed that my cross member is bolted in. It is a 4-spd, which I thought someone on here said had welded in cross members!? Can anyone confirm this one way or ta other? I'm wondering if a previous owner may have changed it over from an auto to 4spd.


[Modified by 81vette, 7:18 PM 11/11/2001]

Monty

I don't know for sure. My '82 also has a bolt in crossmember. Maybe someone more NCRS-like would know if the later C3's used bolt-in crossmembers for both manual and auto tranny's. Several owners of earilier C3's say that the manual tranny cars had weld in crossmembers, while the auto's had bolt in.

norvalwilhelm

Do you guys want to put a mustang transmission in your vet? All tremecs were made for fords not chevy's. The ones you buy are converted over to fit a chev. I just completed this swap and it was easy. The stock 700-R4 driveshaft worked fine. The transmission did clear the crossmember once pushed into place. The weld on front tab for the mount was easy for anyone with a welder. For a shift handle get a mustang one.

zzrck

I'm sure all 4 speed used welded crossmenber from the factory and all automatic the bolted one so you could remove the trans. without having to remove the engine.
I also think that ALL the 1982 Corvette came with an auto trans from the factory.

Magnum '82

Just wanted to say I LOVE YOUR VETTE!!! I was searching for a '80-'82 Red/Tan loaded w/4speed. I settled for a black '82. I like what I have, but I REALLY miss a 4-speed and I still long for a Red/Tan car :sad:

81vette

Interesting...so since I have a bolted in cross member then my car may have been an automatic at some point. Everything on the car was stock when I purchased it. Even the computer chip was the stock unit. I wonder if it is possible that they put a 4sp in a car slated for an automatic at the factory? In any case, it should make upgrading to a 5 or 6 speed relatively easy.