I have a 73 challenger with a 440 with indy heads.. The car is backhalf'd and a 4 link with coil overs and wheelie bars.. The car weighs 3280 WITHOUT the driver and I WISH I could get my 60' in the high fourties... I also have a 5000 stall and a 4.56 gear...33.5X 14X 15 goodyears that DO NOT like to be warmed up too much and the car runs 10.30's at 132 mph.. I think your 60's are where they supposed to be....UNLESS your car weighs 2800lbs!!!