by GreenLake » Thu Aug 15, 2019 3:35 pm
I checked and the ones I bought for the project were 4" opening, but measure 6.5" in outer diameter.
You may check whether the seat fronts fit an 8.5" circle in which case you could get the 6" opening; for this project, the largest size that fits is indicated.
As I mentioned, I didn't go through with this at the time and the reason may well have been that I realized I bought a size too small.
Also, if you wait with installing the deck plate until after you've done the foam removal/replacement, you'll give yourself an extra .25" - .5" of opening to work with as the threads take up some room; that can make quite a difference I found.
~ green ~ lake ~ ~