440 Camshaft recommendations for up to 6-6,500 rpm?

My stock bottom end 440-6pack motor, Team G, 850DP, ported BV 906's, approx 260cfm .650"/.650"[email protected] sft cam, made 527fwhp and pulled 6700 in the traps with slip still pulling with 4.88's/14x32's back in 1990.