Driveshaft seals

[Jbeener1]

Hello to all. I am new to the forum and look forward to learning. I have a 1992 20 hp johnson (J20crend) that I am replacing all the seals in the lower unit. I took out both driveshaft seals and installed the new ones, I was then watching a video of the exact same motor doing the same things that I am doing but before he removed the driveshaft seals he took a measurement from each seal to the top of the seal opening hole then as he installed the new seals he set them inside the opening using the measurements. My question is should I have done this? I just drove them in until they were seated. Thanks for your help