You are talking about the changes to your specific build to make it somewhat streetable, correct? Think you'd be able to run power brakes with the cam LSA change?
Yes, your correct. You should be able to but it really depends on how well the engine is machined and how well it seals, as this has a direct effect on the engine vacuum. This engine in my car had 12-14" of vacuum. 12 on the rich side and 14 on the lean side. Also keep in mind that I used a single plane manifold not a dual plane manifold, this has a tendancy to drop vacuum some too. Also I set the timing at 30* and raising the timing up a few degrees will add more vacuum.
The worst case senerio would be to run a vacuum canister but I don't think that it would be needed.