The difference would be that if it's a bucket seat 71 B-Body it would use the same shifter as an E-Body.
If it's a a bench seat 71 B-Body it takes a special shifter.
The link you posted looks like it's intended for 70 and prior B-Bodies.
This pics shows the different shifter mounting locations.
The top one is A-Body.
The lower one shows the two different mounting locations used by B&E Bodies.
70 and prior B-Bodies use the front one, closest to the main body of the trans.
71 bench seat B-Bodies use that location also with a special shifter mounting bracket and shifter.
E-Bodies and bucket seat 71 up B-Bodies use the location at the rear of the tail housing.