For the big bolt that is in the slot, is there just a flat washer and a nut or is there something special that goes there? I seem to have lost whatever goes on that bolt

Hard to remember but I thought there was a flat rectangular backup nut on tha bolt that as stopped from turning by that raised part on the adapter plate. I could be totally off. Been awhile since I had mine off. I'm supposed to get under there tomorrow. I'll feel around and try and figure it out if you still need it.

That is not a 69 shifter mount.A 69 mount is stamped steel and has a nut welded to it for the large bolt that passes through the sleeve that is in the center of the shifter body.The lower rear bolt goes through a slotted hole in the mount that has a special curved nut on the back of the mount that allows some adjustment fore and aft.I believe that the same curved nut is used on the mount that you have wich I think is from earlier big Pontiac's and A body cars. 68 Firebird may use the same mount as a 69 but I'm not positive.I do know for sure that the 70 and up mount is not the same as the 69.

The trans and shifter is from a GTO. I've got a washer and regular nut on there now. Hopefully I can find the right nut somewhere. The regular nut looks like it may work. I could probably make something out of flat bar and drill and tap

Inline tube has the curved nut for a few dollars.lf you are putting the GTO trans in a Firebird you will find that the speedo cable is on the opposite side of the transmission.

Thanks Andy! Just orders a nut and a couple other things from Inline