need help with 60 ft time

First my car is a 1970 mustang fastback.351 cleveland stroked to a 383.AFD heads,edelbrock air gap intake,750 holey HP carb and frp headers.5 speed tremec trans,and 3.89 gears in the rear.And south side machine lift bars.Engine dynoed at 535 HP.My problem is my 60 ft time.(1.989),my time was 12.297 at 116.40 mph.my tires are M/T ET street radial.Leaving the line around 2500 rpm in 1st gear,but tires are still spining some. this is mainly a street car that i take to the track about 2 times a year.Any pointers for me thanks