ORIGINAL: earlwb
I thought that the Evolution version of the MVVS engines used a different crankcase casting with a big E in it versus the MVVS moniker. But MVVS made the engines for Evolution. Evolution also used a different ignition module in some cases too. Of course Evolution warranties their branded engines.
Earl, small correction:
MVVS makes the parts for Evolution, some of which are different.
Evolution assembles and sells.