Generally you level the carb. The motor is built to give a 4 deg down. (crank shaft/bell housing) This is to facilitate a good pinion angle. It's good to try and install like that. There can be situations where you can deviate.
There is a lot about what you are doing that we don't understand. So just a general answer can be made.


Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn