Obviously it would depend on the engine.
That said, I've known a few with 800-900hp engines that claim nothing is faster, and they've tried them all. *shrugs* it's all beyond my budget.
On a somewhat unrelated note, I'll have a set of these new 660's here tomorrow, and can compare the calibration with the original ones to see if they are on the same level. I'll especially be interested in the emulsion tubes, as they haven't made the originals since the 1960's, the later tubes are vastly different.