Thanks RCGuy!
My last step before building starts is picking the right engines.
http://www.osengines.com/engines/osmg0900.html
Powerful, cheaper than 81s
http://www.osengines.com/engines/osmg0981.html
Good performance, good fit, expensive!
I know the 81s pull the b-25 around well on 12x6x3 props. Can anyone comment on the 95v installs and performance? I'm guessing the opening in the cowl will have to be wider and the engine will stick out more. Are there any other issues?