My car has almost always done this. If I floor it say while in 3rd or 4th when it downshifts to second it will hold second and not up shift! I held it all the way to 6K and it was still climbing. Also will not down shift from 3rd to first unless I really mash the gas pedal I mean stomp it literally.

 

sounds to me like you have a shift kit problem? my friend had a problem where his car would kick back to first at wot. Start looking at the shift kit....was it professionally installed?

 

Yes the shift kit was installed by AMMCO I guess you can call those people professionals. But the funny thing is recently I got into carburetor tuning and the problem had fixed it self after I put the carburetor back on the manifold and readjusted the TV cable (I was told anytime it is disconnected it needs to be readjusted). But recently it got cold again and I had to turn the easy idle screw up some to make it idle higher then the problem came back. If the TV cable is out of adjustment just a little bit I mean really little bit could it cause this problem? When I mean little when you turn the easy idle screw it moves the throttle linkage slightly.

 

im sorry, didnt realize you had carb. to the best of my knowledge the cable only needs to be re-adjusted if the carb is removed. im not really into carbs, had 1 and really didnt like it. although it wasnt properly adjusted and needed rebuilding. i would try posting in the carb discussion for help.