Realistic valvetrain expectations.

If my current lead on a 400 comes together I may be doing my first big block build. What are the limitations of the big block valvetrain in a high end street/strip build? If I do this trick flow heads will definitely be used. The flow numbers seem fairly close to stock LS (square port) heads, and I intend to keep it stock stroke (so c.i. will be similar). I know that 1.5hp per c.i. is no problem on the LS platform in the low to mid 6,000rpm range(and done with a reasonably friendly cam). I have never seen any dynos of Chrysler big blocks performing like this. How heavy is the BBM valvetrain...is it a volume/velocity issue...other? Is 1.5hp/ci even possible at reasonable rpms without a Himalayan cam?