Is this cam too wild for power brakes?

Put it in neutral, and slowly rev it up til you hit about 13 or 14 inches of vacuum. That is about the minimum vacuum required to operate a booster. If it happens at 1200 rpm then That is the minimum rpm to operate the booster.
However if you have a manual trans, compression braking will artificially keep the vacuum up,to a lower rpm.
You have to have the engine idle bugged out, That is; the T-port has to be synced and the idle-timing properly arrived at. If your timing is too retarded the vacuum will be low. If your compression is weak, the vacuum will be weak.If you run too low a rear gear, the vacuum will stay low for a fair few miles per hour.
That cam wants a minimum 3.55 gears and probably a compression ratio up near 10/1
But here is the thing, as soon as the car is moving, the vacuum will rise, and you are good to go.
When coming to a stop, you will be downshifting as you go so the vacuum will remain high enough to just before you clutch it and stop.

I ran the 292/292/108 cam, and my 73 Swinger booster was fine with it. Except at first start. But a couple of blips on the throttle and away I went.
That cam did not like the small dual diaphragm booster.I almost solved that with a 15/16 M/C, but in the end I swapped that booster out.