I assume this is one of the ones you were thinking about. Paul would know more about it than me, but while I expect it to be $$$, my experience has been that heavy truck parts are much more reasonable for comparable items than with light truck parts. Still a bit much for my needs, but it may be worth looking closer at.

Todd    (coffees over... back to work... gotta get this mill up & running)

  Looking at the url doc Paul referenced, it appears these are infinitely variable valves.  If this is the case, it would be more desirable (to me) and worth a few extra ounces (and $). 

 

Mark S.