Percolation? Heat soak? Don't drive during summer??

Another weird recollection which may be of use to helping solve the problem.

When I first got the car put back together, I actually did plenty of 30-45 minute drives down the back streets while trying to adjust my kickdown and throttle cable. I never stalled, got a little hot from all the stop and go but the car never died on me... it wasnt until trying to do the tideous things like go get donuts, go get slurpees, burger King and idle in the garage... thats when it decided to start stalling out...