........the MG66 is manufactured by GO ENGINE. Mark at Massive Mods has been a GO dealer in Australia for a number of years. He has extensive experience modding GO engines. The new GO GX series engines are the 6th generation of engines from GO. The MG66 is of Mark's design.

If I followed the history(thread) correctly the MG66 = Massive/GO/6th generation/6 port.
It's spoken of VERY highly in this thread. It's over 700 pages long tho.
Look for posts around the mid to late '09 time period for the start of MG66.
If I recall correctly, Trey (the U.S. GO importer) sent an MG66 to Neil for testing.

http://www.rctech.net/forum/nitro-of...hread-728.html