Let us beef up the bottom end

Basically I'm envisioning like a slider.
WIth stock in the middle, one extreme will be +max torque +max rpm +weight +cost +longevity -responsiveness, the other extreme being the reverse. Should probably also increase/decrease smoothness in engine layouts that aren't inherently balanced. I see this as allowing for a wider range on engines to be built, as gives a fun, simple mechanic into really letting us build the kind of engine we want, from a super "built" tough-as-nails stump puller (Think the legendary GMC Twin-Six, many of which ran for decades in stationary applications driving well pumps), or super lightweight racing engines that only need to last for perhaps a few dozen hours.