bucket seat question part 2

My friend put b-body seats in his Dart and had too make afew adjustments. He had to install spacers to get the right hight but the bigger problem was seat wasn't on center with steering wheel. He had to move tracks over some to get this right. When he was done they look and fit well.

I'm gonna guess he had to move them in more towards the center of the car? It's gonna be a little more work than I had anticipated, but these seats are nice and the price is great.. So guess I'm gonna go that route. Anyone that can tell me how far in to relocate the holes (using A body seat tracks) I would appreciate it. Also anyone with a part # for the spacers? Thanks everyone