Who knows about the Mk II motor? (re: Bill Thomas)

[Stefano]

Not much is known publicly or written about Bill Thomas and his involvement with General Motors in the early years of performance.

It would surprise me if he was not involved with the Mark II Mystery Motor in some way.

I have traced his connection with GM /Zora Duntov back as far as the late 1950s, where he built the motor and FI (I believe) for one of Jim Jefford's Corvette Race Cars. I can't remember if it was the SR2 or the Purple People Eater MK I.