The tunnel holes are for a 4spd Saginaw with Muncie shifter. I've heard 3spd holes are located differently. As you will see the 4spd hole is toward the driver's side. The ruler is pretty centered on the tunnel.
The tunnel is not exactly centered in the floor. It angles to meet the pinion. I've always wondered if this adds to the sagging problem on the drivers side.
[This message has been edited by bonecrusher67conv (edited 09-17-2002).]