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

Purchased this Dart with a 440 with a Mopar purple for idle to 5,800 (as per the engine shop). Was thinking of going with something to get me into the 6-6,500 range. I know that will sacrifice a smooth idle and depends on heads and valve train. Specs on head and valve-train when I bought them are:
915 heads port and polished,
105# at installed height 1.80
300# at 1.25 .550 lift
coil bind 1.10
good to .600 lift
I an not an expert on these calculations. Any suggestions as to what would work best to get me into a higher rpm zone? Purpose = street and informal timing at airport strip.
Take a look at 250-260 duration camshafts you'll get what you desire. I can't tell you lift since I don't know your clearances between valve & pistons..youll need a torque converter too