you don't need an adaptor. there is a another starter that bolts up into the block, rather than into the the bellhousing. one just has to make sure that they have the correct flywheel with the corresponding nbr of teeth to go with which starter
ron

http://s908.beta.photobucket.com/user/padresag/library/turned%20works
http://s908.beta.photobucket.com/user/padresag/library/furniture
and a little history of where I come from
http://forum.woodenboat.com/showthread.php?156542-old-boatshop-in-Steveston