C3 conversion: transmission (6SPD) and engine (LT1)
Thread Starter
Instructor
Joined: Aug 2004
Posts: 174
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From: Atlanta Georgia
C3 conversion: transmission (6SPD) and engine (LT1)
I am looking for information regarding a conversion I plan to start on my 1981 Vette. I have been told that a 1995 Vette 6SPD tranny (ZF) will not fit in the transmission tunnel of a 1981 Vette without major modifications. I also understand that a 1995 Vette LT1 would be an easy fit for this 1981 car as well. I currently have a 1995 Vette (53K miles) with engine and transmission for parts. Additionally, it has been suggested that the Camaro T56 transmission is best suited for my application because of size and durability. I am also contemplating putting a 1997 Camaro LT1 engine in this 1981 car since I have access to a 1997 Camaro LT1 and T56 with low mileage. Any information you have regarding this conversion would be extremely helpful to me. If you have any other insight for me on this conversion, please feel free to share your thoughts.
Thanks in advance for your help.
Thanks in advance for your help.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
The ZF will fit if you widen the tunnel but the T56 is a much easier fit. The ZF has the added problem of only being available with the torque arm mount so you have to build your own transmission mount. I have modified all these things to fit the ZF in my car and it fits but it's real snug and I may actually cut away the transmission tunnel and weld in a custom one to give the tranny more room.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
Originally Posted by 24Hours
What engine did you bolt the tranny too? If you had to do it over again, would you put in a T56?
Here's my trans mount:
As you till probably notice, the crossmember is a custom job also, the entire center section is built from scratch. I also modified the bracket that holds the shifter (the thing with the round hole) so to give more room, I'm using a TH400 yoke and otherwise it wouldn't slide in far enough so I did that to give more clearance.
This is how close the fit is, near the firewall it isn't a problem but at the rear it is. I had to cut open the floor quite a bit for the shifter to go through and the tranny mounting bracket I made actually pokes through the hole, it's higher than the floor used to be in that area.
Racer
Joined: Aug 2004
Posts: 399
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From: Chambersburg PA
No Cut overdrive option
24 Keisler Engineering has a bolt on No Cut system for the C3 that will yeild you a .64 overdrive. I cosidered a 6 speed but really fond no need for the second .50 overdrive. The TKO will handle upto 650hp and requires no change to yor car.
Racer
Joined: Aug 2004
Posts: 470
Likes: 0
From: South Florida
Originally Posted by 24Hours
I am looking for information regarding a conversion I plan to start on my 1981 Vette. I have been told that a 1995 Vette 6SPD tranny (ZF) will not fit in the transmission tunnel of a 1981 Vette without major modifications. I also understand that a 1995 Vette LT1 would be an easy fit for this 1981 car as well. I currently have a 1995 Vette (53K miles) with engine and transmission for parts. Additionally, it has been suggested that the Camaro T56 transmission is best suited for my application because of size and durability. I am also contemplating putting a 1997 Camaro LT1 engine in this 1981 car since I have access to a 1997 Camaro LT1 and T56 with low mileage. Any information you have regarding this conversion would be extremely helpful to me. If you have any other insight for me on this conversion, please feel free to share your thoughts.
Thanks in advance for your help.
Thanks in advance for your help.
http://www.vetteweb.com/tech/0407vet_6speed/
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Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
Originally Posted by 24Hours
How did that effect the interior of your car when you modified the tunnel?
