B and E bodies are completely different cars than an a-body. I am in the dark as to what it is you do not understand. Are you saying that all the tunnels are the same size? They are not. For what it is woth a gm4l80 e will fit into a Challenger with NO cutting of the tunnel, into an a-body it requires MAJOR surgery. Let me try to find the pictures of the Challenger......the first picture is of a Challenger with a 4l80 in it. Notice how the area near the mount is not cut in anyway. The second is of my car from the bottom, notice how much farther back the trans mount is in relation to the where the torsion bar is mounted, which is the location of the factory trans mount. Being that the trans mount area is the same from the bellhousing to the trans mount on both cars, that shows you how much longer the Challenger tunnel is than an A-body. That is why the 518, or in case of the pictures, a 4l80 will fit into a Challenger with no cutting yet require a ton of it to get it into an a-body. Last picture is of my car from the top. notice how close my hole is in relation to the gas pedal? Go look at your car and see the difference from the edge of your tunnel to the pedal in relationship to mine? On a Challenger, the tunnel was not modified at all. Sure, you could just drop the tail shaft down to clear everything, but what will that do to driveline angles??
