my 69 340 swinger

Hey guys, when I bought my Dart years ago I installed a Formula S 4 speed cam . The engine is basicly stock with the exception of an LD-340 intake . It has an automatic tranny w/ stock 3:23 gears . The issue I have is its such a dog off the line but I really like the rough idle . Should I change out the cam again to something different or what . I do have a set of 3:91's I would like to use. Thanx for your help.