I'm using Cosworth cams. We tried to buy Crower, but the backlog was months. Until I get the trans built, I can't really say how well they work. For sure, we'll be well over 400/400 on a very conservative Mustang dyno. The trick, as you well know, is to figure out what you want out of an engine, and for what reasons, and then to put a package together that does exactly that. I really don't think it's necessary to P&P for most people. Simply deshroud the heads, make sure the valves fit properly. What a lot of people don't seem to realize is that whether or not you keep the stock cams, if you are going to try for big hp, then you better get new springs and retainers.
Hey, how do you like your ACT clutch? I put in a ClutchMaster 200, and it sucks big time. No way, no how can you avoid chatter in all gears, up and down both.