Classic/Antique Car Repair: IDILING PROBLEMS, electronic conversion, torque converter

Question
I OWN A 1970 CORVETTE 350 300HP. AFTER DRIVING ON THE HIGHWAY OR ON A LONG DRIVE WITHOUT STOPPING FOR 40-50 MIN, WHEN I REACH A TRAFFIC LIGHT MY IDLE STARTS TO DROP AND JUMPS BACK UP. IF I PUT THE CAR IN NEUTRAL THE IDLE STAYS STEADY, IF I KEEP IT IN DRIVE WHEN I AM AT A LIGHT OCCASIONALLY IT STALLS, AND WHEN I AM READY TO ACCELERATE, THERE IS A SMALL HESITATION BEFORE IT PICKS UP. WHEN I AM DRIVING ITS FINE. I HAVE DONE THE ELECTRONIC CONVERSION KIT TO GET RID OF THE OLD POINTS SYSTEM. THANKS

Answer
Jimmy, it sounds like a carburetion problem in the making. If it were a later model car with a lock up torque converter transmission I might suspect that, but an early carbureted car It could be a carburetor out of adjustment, and that would include float level. The small hesitation could be a low or high float level or an accelerator pump failing. It could also be low spark plug firing voltage but that should also effect high speed performance and performance under load.
Brad