fin placement stand up paddleboards

Hello all. cananyone help me with fin placement on sup"s . Im trying to build three different sizes 8ft 9ft and 19ft  2+1 set up I kinda know where the single fin box goes but need massive help on the sidebites… so How far up from tail ? how far off rail? How much toe in ? how many degress? please top bulders Help!

16 inches for the front set. I’ve measured many of the top brands. 16 seems to be, almost an industry standard for SUP.