Merc engines have pretty good specific output, not to mention Merc can put as many valves as they want in their heads since they're in the high end market. In fact, Audi's been using five valve heads on some of their engines! And, the Variable Valve Timing can do a lot of good. Forget about Honda's spiky VTEC, many other manufacturers, including the Germans, have had continuously variable valve timing rigs for years. It's way smoother than VTEC; you just feel a nice swell of power as the cam timing changes thru the rev range. I really think this is going to be a great engine. I will admit I'd prefer 4v heads, if for nothing else, the symmetry and classic hi po rep. that they have. But if 3v heads work for Merc, I'm sure they can't be that bad.