confused - or just a stupid question

The gear is a 8 1/4 with a 2:76 gear. Probably the original rear end. I am hoping to upgrade that sometime down the road. I know its more for economy. The transmission is the original 904 torqueflight. It was rebuilt with the engine and just has a stock replacment convertor. I don't know what the stock stall is. Thats a field that I don't know too well. When the timing gets to its best spot, maybe that will make a difference. Just about any car can spin the tires. Something has to be wrong somewhere. If it could burnout out before, it should be able to do it now effortlessly.