Hi everyone.
The title may sound a tad weird, usually people to the opposite.
Here's the deal.
For my complete restoration I've been given a new complete birdcage that came from an manual Vette. Rigth now my tranny is auto.
I plan to convert to manual, but not now for $$$ reason.
Since I want to move on, I'm looking for a way to have my auto tranny to work with the manual transmission tunnel, without touching the tunnel itself.
What kind of shifter would fit and what kind of linkage I should get/fab?

 

not certain of the year you are referring to, but i'm pretty certain that all you would need to do is make some temporary plate to cover the manual trans tunnel opening since the auto shifter mounts on top of the tunnel and operates the automatic trans via a cable (unlike the shifter mechanism on the manual that is mounted to the trans and cross member and needs to come through an opening in the tunnel itself. since there should be a tunnel boot to seal the shifter handle somewhat on the manual, once it (the shifter) is removed it may be enough. the auto shifter might mount behind the opening, but i'm not certain. other than the cut out however there is no difference in the tunnel itself as far as mounting the shifter on top (auto) as opposed to through it (4 speed)

 

I believe the '76 tunnels were the same for both auto and manual. It was when they moved to steel tunnels in '77 that they were specific to auto or manual.

 

I'm not sure about the year of my donor birdcage, but it differs from my former auto '76 birdcage.
I'll post pictures this evening.

 

i have a 78 and (since i am in the process of converting from OEM auto 350 to OEM muncie 4 speed) i don't believe there is any difference in the actual tunnel except for the actual cut out allowing the 4 speed shifter to enter the cabin from it's mounting on the trans and cross member. additionally, there is no difference in the frame auto to 4 speed (cross member) and the trans mounting bracket is identical regardless of auto or 4 speed application. even though they appear to be the same, however, there is a difference in the drive shaft (propeller shaft) length. the 4 spd shaft is slightly longer. i believe that all came into being with the 77 (could have been the 76) model year frame. i guess the tip off would be if the cross member is removable (pre 77) or not as far as dating it. again, if it is a "newer" frame, it should bolt up and the only alteration might be the hole needed to pass the shifter handle through the tunnel to the cabin. to get your auto trans to work with your non auto birdcage should only require you to mount the auto shifter ON TOP of the tunnel and route the shifter cable to the rear like the original auto birdcage. it should only require that you drill holes for the shifter mounting bracket on top of the tunnel. you might want to cut out a piece of sheet steel or something similar, remove the 4 speed tunnel boot, and cover (even if it is temporary) that opening and use the same holes to secure the cover to seal it (i would use some silicone sealant also). you could always just remove the cover and then make whatever frame changes might be necessary to changeover to a 4 speed in the future as you indicate.

 

What year? Through 75 and possibly later, the fiberglass floor was cut and a bump out panel bonded in for the AT option cars to allow the AT to clear the underbody. The regular manual transmission floors will not fit the AT.

Purchase the AIM for your year and take a look at the optional AT installation. The AIM shows were the underbody was cut, the bump out bonded in, larger shifter hole in the hump, etc., that the AT cars required.

For steel floored cars, the underbody and floor pans are essentially configured for the AT since most of these cars were AT. The 4 spd fits the AT floor.

 

All vehicles up to and including 1975 and some 1976's with the TH400 had a bump in the pass side front tunnel to acommodate the side mounted modulator valve of the 400.
If you have that bump, all stock trannies will fit. Other wise you must use a TH350 with no side tunnel mods. You also need the proper cable and boot assembly for the auto.