Installing Bracket on enclosed transom

[RWatts23]

We just got the new transom in and enclosed. I'll be ordering my bracket on Monday and wou;d like to to mount it/pre-fit every thing before we install the cap and live well that will go in the new transom. My question is roughly at what height does it need to sit above the chine?? I have a yam 250 and will be looking at a 250-300 four stroke next year.