One thing to remember when you get a frame powder coated (or even painted), the ground or earthing return to the battery, relies on bare metal contact between the frame and engine to properly work .
On the '78-'80 model year bikes the main grounding or earthing point is the forward ignition coil mount, I don't have one of these bikes, so I don't know if there is a place for a screw or bolt to thread into the frame or not, but if there is a threaded hole for it, it must be clean of paint or powder coat, down to bare metal .
On the '81 and later model year bikes the main ground or earthing point is one of the screw that holds the voltage regulator on, those threads must be clear and free of powder coat, or none of the bikes electrical circuits will work properly, if at all .
The only contact points between the engine and frame, are where the two engine mount studs go through .