You are asking for “all years” of the New Design boat. You will need to install inspection ports on both the starboard and port sides of the anchor locker to access the aft mounts. I believe that 4” will work, you can do a search on this forum to confirm what others have installed. My research indicated 4” ports will work for me but, I have an ‘88 boat and I do not know if your ‘87 anchor locker is different from mine. This is one of those “future projects” for me. I have both the hole saw and inspection ports ready and waiting for when the time comes. The hole saw is daunting. I don’t look forward to this project! lol
Keep in mind that when shopping for inspection ports what you see is the outside of the sealing plate and it makes the inspection port look much larger than the hole cut out dimension. The best thing IMO is if you can, purchase the inspection ports and then locate the inspection port support plates in place and then see exactly where and how the ports fit in your anchor locker.
George