no third gear

[QUOTE='64 Cuda]The linkage should be adjusted so that the rod to the trans is all of the way back when the throttle is all the way open.[/QUOTE]

This is usually the case but not allways. Since his don't want to shift into 3rd he may have to adjust it so it don't push it all the way back.

Robb the linkage going to the trans. (the slotted part) is threaded onto the part that you said is a sort of "J" hook. There is a lock nut there that is a 1/2". Loosen that locknut and thread your slotted part on farther by 2-3 turns so it's like the trans linkage isn't being pushed back as far when your pushing your throttle down. Test drive it and see how it does and post back with your results.