There is an excellent thread on the installation of the firewall bushing. I was all set to follow this thru to replace a bushing in a '75. I started with the disconection of the firewall to trans linkage. And stopped to post this. The full instructions call for getting into the cabin shift lever space to allow for the full forward pull of the shift linkage in the tunnel so the bushing can be inserted in the firewall. Why do I have to do this. Can't I just slip it over the tunnel link that is protruding from the firewall and work into place? Looks "do able". What am I missing???

That bushing is a pretty tight fit. It's allready somewhat of a pain to install without the shiftrod in place. The bushing has to flex in some way to get in the hole so with the rod in place there's no more room for the flexing...

To make the job as easy as possible, first BE SURE you have the correct bushing for your car. Next, remove the 4 bolts holding the shift lever assembly in place. DO NOT loosen or remove the pinch bolt where the shifter clamps to the forward rod. Pull the assembly as far forward as possible. Install the bushing. Insert the rod through the newly installed bushing and bolt the shifter assembly back in position. No muss, no fuss, and NO ADJUSTING!

The Cap'n

Don't worry you can gain access to the shift rod again through the steel access plat in the tunnel just at the base of the firewall.
I gaurantee it WILL NOT go in with the shift rod inplace.

I tried to do exactly what you asked and the bushing needs to compress just enough that you cant leave the rod protruding. It was ridiculously easy to install once I pulled the rod into the tunnel.

As usual the Cap'n is correct.