A. J,, an engine, any engine, will be shown it's peak Torque point on a Dyno, and an engine's peak Torque point is where that engine is most efficient,

and know that different mufflers can alter an engine's powerband a bit,

the "older" OS link below should help with your FP engines, OS suggest the average 46 engine to have it's peak Torque around 12.500 to 13.000, and with that, the old school rule of thumb tells us that the smaller the engine the higher it's peak Torque point is on it's powerband, so this tells us that propping your 35 around 12.700 to 13.00 will get you in the ball park

https://www.osengines.com/faq/faq-q686.html

Jim