FWIW, the specs on your cam are nearly identical to what another SPF owner (Terry Brown #930) is running with his Webers. Comp Cam Xtreme Energy Cam XE282HR-12. Same duration with int lift at .565" and exhaust at .574". That cam is ground on 112 degree lobe separation. I would suspect that yours is similar (a higher number promotes better engine vacuum). I've run cams with 110* and my power brakes worked fine.
I'm definitely not the source to help you with tuning, but I've kept a lot of notes on the subject in the event I ever decide to spend five grand on basic carburation.
I'm running a Comp grind with 540 lift, 240* int / 246 exh @ .050 duration (running way more duration than you) and on 110* lobe centers. Just too much cam to tune Webers with.