Put this in Google and you will see many posts about internally regulated alternators: site:matronics.com internally regulated alternators
Also a good FAQ here discussing internally-regulated alternators
http://www.aeroelectric.com/FAQ/Aero...c-List_FAQ.pdf
It is pretty easy to modify a Denso for an external regulator See
http://www.eaa.org/experimenter/arti...alternator.asp
There are many versions of Denso with small differences in mounts. You might heat up the bracket and bend it to fit. Done that. Whatever you do, the bracket cannot put any twisting force on the Lycoming case where it bolts up. It will crack the case.