I'm new to this forum, but I do remember the old OPS .60 engine. Around here a lot of guys ran them in C class deep vees, monos, outrigger hydros, and in 1/8 scale hydro back in the late 70's. After the .60 came out, OPS came out with the gold headed .65, and later the .67 which competed with the then new K&B 11cc .67. As for your .60, I think parts will be difficult to find, at best. If you have a boat powered by the .60 that you're dying to get running again, I'd suggest selling it, and getting the more recent manufactured OPS .67.