Up until recently the sim rides were done in the 767, but that has become overbooked and now is in the 747.
767 was in used when I went for a ride. The reason I got was that the Dash8 was too busy. Besides it doesnt matter what aircraft you do the sim in. They are not looking to see if you can fly a 767 or a 747 etc, just looking to see if you can fly IFR, and how good your scan is.