Ben, Are you running a stud girdle? I am a Firm Believer that any cam running non stock geometry and / or spring pressure should have quality girdles installed.
As a sanity check for the need = slip the girdle down over the rocker studs with bar loose but tight enough to hold its own weight. Now bar the engine over about 180 crank degrees. You will see that the girdle may slip or fall down tp touch the spring caps. If just rolling engine over by hand moves the studs from their position enough to LET Girdle slip down think how much they are dancing around at a whimpy 4 or 5 thousand RPM.
The cheaper girdles with a U bolt for each stud are a pain in the ass to adjust, leave many more nuts to loosen or fail and clamp with less force than split bar design but are still better than nothing.
http://www.dartheads.com/manager/upl...talog%2004.pdf