I finally got around to putting a 6S Power System into my FF-Demon RC Plane. I ended up choosing a T-Motor F90 Pro 1300KV drone motor, with a Cobra 60A Race Wing ESC with BLHeli firmware and an HRB 6S 1800mah 50C battery. I tested the power system with a n APC 7x6 Sport Prop and 7x5 Sport Prop. The high pole drone motors work best if you use a BLHeli ESC, they are much better a keeping up with high Pole motors at high RPMs. Below are links to the parts and the video of the Maiden Flight with the new power system. In the video the plane hits a GPS clock of just over 120mph. Not too bad for a foamboard plane!
Link to Motor: T-Motor F90 1300KV/1500KV Motor (getfpv.com)
Link to battery: https://amzn.to/3lMf57G