Almost any gas engine can be shoehorned in to a normal hull. Obviously, the Lobster and outrigger Pak are not normal hulls so they would require an engine that is narrow to keep the scale look. The big issue is accessibility. A side exhaust boat would probably have to have the pipe under the deck or use wrap to center header for example. I'm looking at a CMB 27 for a boat I'm building but, then again, the cost may have me looking at other options before all is said and done. Offsetting a side exhaust won't work since the carb is on the oposite side and, therefore, would become totally nonaccessible for maintenance or tweaking as needed. Leaning the engine to the exhaust side would lower the plug height as would installing a belly pan. What boat are you looking at building?