I had that cam in my 440 Charger and it wanted shifted at 6200-6300 (4.10 axle, mild ported iron heads, 800 DP, CH4B intake, 9.4 CR, 4260# curb weight.) Anything lower slowed it down. And ET's were flat up to shifting at 6700 rpm. So I shifted at 6200-ish to save the motor.