I noticed the firewall cutout for the steering column is pretty generous. My steering column is about 1/4" off center away from the headers, giving 1/2" clearance at the closest shifter position. Maybe other body styles or earlier year dashes bring the steering column closer to the headers. The position of the steering column depends on the steering box that's mounted to the frame and the clamp mount on the dash.
Screw Rubiks, I won't give that name to something that has been around way before Rubiks even existed. From the first time someone picked up a tool to modify something, generally there are a half dozen or more "changes" and "improvements" to go with it. Rubiks, screw that he had nothing to do with it