for my od on the 40 it was mounted on the bottom of the dash left of the steering column. there were factory drilled holes already there for i dont know what so i used them. i had the modern blank pto knob. if i ever get the od back on im going with the one dave used
as for the routing of the cable id say where ever it puts the least amound of bend in the cable to decrease the friction factor. my cable went through the firewall where the main wiring harness goes through since i have ample room to run it that way plus it was right in line of where i mounted the bracket to the dash
