BTW, it appears from a look at Miller's website (MID-LIFT.COM ENTRY PAGE
) that the older PA series mid-lift rockers are available at $342/set. There's also a "G-tool" for $208. Online instructions are visible for both. Pretty interesting!
I also read somewhere that as this concept has been around for a long time and in fact was endorsed by Chevy racing some time back, GM since decided upon the "66% rule" (mid-lift would be the 50% rule by analogy) to minimize wear and tear at high spring loads during the last phases of valve opening. Don't know much about that.