Here is my CB750 with a 3" inlet Supertrapp on the 4 to 1 exhaust. There is a bracket welded on the outside that lines right up with the rear pass. peg. I guess you can see that in the photo
Anyhow, the motor is stock, it sounds great, all of the baffles are off, stock airbox with 4 2" holes cut in the back, K&N filter, 135 mains, lowest notch on the needle.