I don't like the xe285hl cam. Have one in my 440 with 10.6 compression, aluminum heads, and aluminum single plane intake. Installed at comps specs (106 icl) it's done at 5400 rpm. The comp valve train will allow it to rev up above 6 without valve float. I suppose if you retarded the cam timing a couple of degrees you could raise the peak hp rpm number. My engine on the demo made 500 ft lbs of torque from 3900-4800 and 475 peak hp at 5400. It's also going into a 72 charger.