74 Dart Stalls when in gear.

One more quick point: this car had been sitting for quite a while when I bought it and I believe it was out of gas 'cause we had to go get 5 Gal's & dump it in the tank. Maybe some Schmutz was partially blocking the Ports or something else in the fuel delivery system. All I can do is change filter, Add Stabil and hope for the best.