On my 440-6, I went with a hyd. flat tappet cam with about 250 degrees of duration (@.050") and .550 lift. I ran long tube headers as well. What made a HUGE difference was having the carbs dialed in by someone who specifically knows six pack systems really well. Most of us know how to change, jets and power valves, but there are guys out there who know what factory 3x2 systems need to work with a bigger cam. I had a NHRA Sportsman Class guy do mine, and it was night and day.
As far as your camshaft goes, the duration on the camshaft is what forms your power-band. You're running good heads that can easily take advantage of more duration than you're wanting to run. The limiting factor in your combination (as it relates to a cam choice) appears to be your stall speed. With 2000-2500 rpm stall (perfect for the street) I think you're going to want a camshaft with between 230-240 duration at .050" lift on a 440. Any more duation and I think you may need more stall to match.
I agree an LSA of 112 may be a good choice for your power brakes. A general rule of thumb is that the tighter the LSA (bigger number) the more tame your idle characteristics will become and more engine vacuum you'll produce. So an LSA of 112 will idle smoother than say a wider LSA of 108 degrees.
Don't spread misinformation about LSA, L
obe separation angles means when the cam lobe is at max lift from TDC, the same lobes ground on 104 LSA will have a lot rougher idle with less manifold vacuum than a cam with the same lobes ground on a 112 LSA due to less over lap at TDC on the wider LSA
Another change by widening or tightening or widening the LSA with the same lobes is generally tighter makes more bottom end losing top end power and wider loses bottom end while gaining more power higher in the RPM band.
Poor flowing heads like tighter LSA to benefit the bottom end and better heads can use wider LSA with more duration and lift to allow the motor to make peak HP at a higher RPM. Don't forget that the lobe design and how much lift and duration as well a LSA need to be optimized to get the best results from any motor and combination of race parts or street and strip parts
