if you're keeping a clutch you bolt the gearbox to a flat plate with a bearing in the center and fit a flywheel to it, have the motor driving the flywheel
if you're not bothering with a clutch you can go with a flat plate the same and have the input shaft driven directly by the motor... or some people remove the bellhousing and join motor directly to gearbox a bunch of different ways
motors are a lot smoother than engines so there's no problem with pulses in speed/power from them
if you're not bothering with a clutch you can go with a flat plate the same and have the input shaft driven directly by the motor... or some people remove the bellhousing and join motor directly to gearbox a bunch of different ways
motors are a lot smoother than engines so there's no problem with pulses in speed/power from them