mastkey-dunno if this will help, but I'm almost certain that I remember some kind of mechanical kickdown linkage on the 327/powerglide in my father's dearly departed '68 Camaro ragtop (ahh...yet ANOTHER ONE that got away!) Take a look around along the sides of the tranny just above the oil pan rails, and see if anything is hanging out in mid-air looking like it should be connected to something. Best of luck.
Wannabe
P.S. My personal vote would be to swap in a TH 2004R auto overdrive....but that's just my $.02
