SOLVED! The issue was a bad ground -- battery to block. But a most unusual one. The test that brought it out was disconnecting battery ground cable, Neg DVM lead to neg batt and pos lead to disconnected cable. Bingo, 0.2v. All grounds good except at the block. It was more than tight and not corroded. But, after disconnecting and inspecting the cable end, it was not truly flat where attached to block. Not bent, just not really flat even though a star washer was used, apparently preventing solid contact. But this cable has been this way for over 6 years and has never been touched. Go figure. Filed flat, reattached and it cranked.
Thanks for the help!
Thanks for the help!