Car stalling in Drive and reverse???

Hello Fellas, I'm almost out of hair from pulling so much of it out. I have a 66 coupe 289 A/T. Here's my dilema...a couple of days ago driving home from work and driving off the freeway, my car starting sputtering and eventually stalled out. I did start the car back up and drove until the next stop light and whamo, same thing stalled out when hit the gas. Did that about 5 times until I got home. In park, car sounds good and same thing when in Neutral. As soon as I put it in Drive or Rev. gets rough and stalls. Only when at temperature. When cold drives fine. ???

Here's what I have done: Checked timing, spark plugs, wires, fuel filter, carb settings all normal. Any other suggestions would be greatly appreciated.

Thanks!

Thanks guys! It wasn't a vacuum leak and the carb was perfect. It was a bad ignition coil. Replaced it a few days ago and the car is running great. I put the old one back just to test it and after it got hot the car started acting up again. Thanks for the suggestions.