Outboard bracket height

[Jaysea]

I’m fitting a Garelick bracket with a Yamaha. F4 long shaft. Looking for mounting height suggestions to give me a starting point. The range on the bracket is 8.5” and the motor bracket top to anti-cav plate is 22”. The bracket has 4 positions so I’m thinking I’d use the last but one for a smooth water setting and reserve the last for wave conditions where I might want more motor depth and forego ideal anti cavitation plate submersion depth, if the bracket range allows.

If anyone has this bracket and a long shaft I’d appreciate your suggestions on mounting height/ position on the transom. Also, what is the transom thickness? 

Thanks