Showa SFF Spring A Kit Fork Help

I recently came across some used A Kit SFF Spring forks. The previous owner stated they were used on a 2016 KX250F. I figured it was a good deal and I would like to have the A Kit on my 2017 KX450F. Upon further and in possession inspection, the forks are definitely used and have some wear showing. The biggest concern I have is the fork length. They seem to look shorter then my OEM forks. Turns out the Lower Fork Tube is roughly 1" shorter then OEM. The Upper fork tubes are nearly the same.

I guess my concern or questions are; Is this typical for A Kit forks to be shorter then OEM? Can they be lengthened to match OEM specifications? Since they are shorter, this will obviously change the way the bike handles, correct?

I called the Suspension company (Lainer Suspension out of Riverside, CA) and he told me to back out my preload and that should do it...I cant imagine backing out a adjustment would drop the fork tube 1".

I planned on shipping them to PC for service/set up, but if they can't be adjusted to OEM specifications maybe its not worth it.

Does anyone know if the fork length changed throughout the years of production...I understand these forks could be 5-8 years old...not sure.

Thank you