Man it's hard to shoe-horn them into most planes. I have a few of them and haven't ever settled on a single engine plane yet. I'd try a old-style 60 sized pattern plane..maybe a King Kobra or something. Any plane that has a cowl is a drag since they really need wood beams to mount to...King Kobra has a cowl...
Finally have a plane to mount a pair of them in, a 85" Duellist.
Wood cowls so you can carry the mounting beams out past the "firewall"..which won't be there..anyway..
Glad to hear somebody else has seen the power of the RIRE Rossi 90..they are beasts!