Advice needed

my 70 duster thats 3200 with me went 7.44 with 240/140 at 500 and a comp 282xs cam 520/540 the mph was down and the 60 was **** if i could had a better hook the car would have been faster 60' times best was 1.67 and best mph was 90 most of the time was 89. something.....i really like the comp cam its nice on the street and great at the track....oh i had a 950 carb on it aswell mike