Actually just found this gem on CL. Twin 55's. Seems a bit underpowered to me but just shows they do exist.
http://jacksonville.craigslist.org/boa/5677291144.html
Also found locally a '73 center console with the 165hp IB/OB. I really wanted an IB/OB before I bought mine but couldn't pass up the deal I got on mine. However having a second V-20 can't be such a bad thing.
http://norfolk.craigslist.org/boa/5634075310.html
Either of these members boats?