I ran my YS .61 with a Hatori 650 pipe set 18" from the first baffle in the pipe to the glow plug running 10% fuel, Rossi R7 or 8 plugs and APC 12X12 or 12X13 props. Use any mount you are comfortable with as these are smooth running engines. I've run them on the mounts that were nothing more than an aluminum plate bolted to the back plate on the engine with four lord mounts, hard mounted directly to the firewall and a home made mount made out of two aluminum rails with rubber surrounding the mounting lugs of the engine.

I can't answer the airframe questions, but the last model I flew with this engine was an R/C City Cursor back in '91.

John