I want to channel my 30 Model A enough to hide the frame. I had a 4x4 piece of angle made to do the channel as in the Eastwood video. If I set the channel on top of the sub frame, just inside the door jam, I gain an inch, which puts me at a five inch channel. This seems to make the cab height too low. I was also wanting to do a three inch chop. Has anyone done a channel and chop at these dimensions? Can you still drive the car without rubbing your head on top?