318 cam shaft selection/upgrade for stock engine

my 323 with a Mopar Performance P4452757AE cam Kit with milled 360 heads, Eddy RPM intake 7176 and a 625 Street Demon carb with 3.55 rear gears. It works great, idles nice, good vacuum, lots of low end grunt and goes like hell for a 318 .30 over.
Purple Shaft Hydraulic Camshaft & Lifter Kit
Chrysler 273, 318, 340, 360
Advertised Duration: 248°/256°
Centerline: 110°
Lift: .410"/.425"
RPM Range: 1000 to 5000
Duration at .050'': 211°/218°