Gary:
Regarding the V8-powered L4's, there are 5 flying, six others delivered but
aircraft incomplete, two more to be delivered within a month, and several
more scheduled further out.

RE IO-540-powered-L4's, Brent Regan developed the hardware for the
installation, including the special sump and other bits to implement the
bed-type mounting which the L4 mount structure expects, and other items. His
L4 has won a few races, and he would be the one to quiz about the difficulty
of the installation. I think the bits he developed are available from Ken
Tunnel (LyCon in Visalia CA).

RE Lycoming hot starts, that is a non-issue if you follow the correct
procedure. I flew and instructed for many hours in IO-540 (including the
factory Glasair-3) and TSIO-540-powered aircraft, as well as IO-360-powered
aircraft, which you correctly observed uses the same FI system as the -540).

Never had a hot-start problem (again, with the correct procedure).

Jack Kane