74 Duster weight loss program

Do you have an auto or 4 speed? Just to let you know, my car was running 12.3 with the stock converter and when I switched to a good one, the car ran 11.5's. Almost a full second with a $450 converter.
I dropped .4 tenths 13.30's to 12.90's by going from an 11 inch converter to a 10 inch convertor. Trap speed stayed the same, though