Yes the lobe separation angle will effect the horsepower but not so much the way you think. Here are two applications on the dyno, changing the LSA only. I widen the LSA for mostly these reasons on NA engines, idle quality and vacuum.
People on this forum are tired of hearing me say this, but here it is again.
Daddy told me when he was building engines in NASCAR, "Jimmy, there are three secrets to building horsepower. The first two are cylinder heads. Third and most important........cylinder heads!"
You're outta air sir.
I ran a 451 with iron heads and 290 cfm. It made 621 HP @ 6,100 rpm. Now that you know what unported Victor heads really flow, check any cfm vs cubic inches and rpm calculator and see what rpm your engine is done.