You apparently didn't see or follow the link in the newest slant build on the Hot Rod site, what You're looking for is right there, though I don't believe they used beehives..
...You certainly could. Took a bunch of valve-side mass out going to late model Ford 2.3/2.5 valves....look to be 7mm stems, scroll down the slanty forum and the thread is
right there. BTW, a beehive is not just for "hi-revving" apps, it can maintain superior control over a broader cyclic spectrum....with the resultant increase in output. Many
OE apps today have conical/beehive style springs, and most never see the far side of 6500rpm, or 6000rpm for that matter.
