An update on the flow numbers. Keep in mind that this head is intended as a replacement for the original head.
The intake flows in the 350 cfm range from .400 lift on up. That's about where an OEM Ford stock Boss head flows. The low lift flows are very good, for instance 181 cfm at .200 lift and and 275 cfm at .300 lift.
The exhaust flows 110 cfm at .200, 158 cfm at .300 and 211 cfm at .400, and 226 cfm at .500 and climbs gradually from there.
Stock Boss heads respond well to professional porting as can be seen at this webite: (Note, I have no affiliation with this shop, just providing a link for information purposes).
http://www.j-performance.com/index.php?option=com_content&task=view&id=29
The stock Nascar rocker worked better than expected. The stock intake does scrub across the intake valve tip more than would be desireable. For a street engine, this cam was probably a little more than stock rockers could handle in extended cruising.
We had two cams for the test, but found the smaller of the two had a damaged distributor gear apparently from a previous owner running a cast distributor gear. At last moment a larger mechanical roller cam was installed which was .674 intake and .685 exhaust lifts with a 112 lobe separation. I didn't know this so the smaller cam figures were given above.
To get into a discussion about particular cams for hemi engines should probably be another thread as no doubt it would get fairly esoteric especially considering that the Boss 429 is actually a quenched shallow hemi chamber with an offset "shotgun" intake port.
The stock rockers actually worked better than we expected. For the gentleman above inquiring about beefing up the intake rocker pad area, these heads are made with much better A356-T6 aluminum so the actual threads in this hole are stronger. Also Eric is implementing several changes in the rocker shaft stand design which should really help the stability. But from what you have described it sounds like you might have been experiencing valve train harmonics.
Here's another Youtube video of the engine on a dyno with the tunnel ram.
http://www.youtube.com/watch?v=6CXjoyuia-I