Re: is my outboard the right hight
Slate,
Will find the sweet engine/transom height match under trial and error, play with shims heights untill water flow skims just under small upper water deflector plate to get the best prop trust out of that 9.8 HP.
A 320 sib is rated minimum 9.9 and max 15 HP, probably will be underpowered with a 9.8 which has nothing to do with a 9.9/15 HP, 80 CC difference. To plane or not to plane will depend entirely on how well you have tubes, keel inflated to, proper engine/transom height seated, trim, weigh ballanced, number of boaters and that's on flat calm no windy cond.
Happy Boating