I removed them, but I didn't cut them. I just bundled the wires and taped them and tucked them neatly in the corner of the car.
If you have no AC or heater then all you really need for a typical SBC swap is one +12V wire for the electric choke on your qjet *if youre keeping that.
I got mechanical sensors, so I have literally 1 wire going to my motor (not including starter wiring).