Anticav plate/boat's bottom height parameters are just a refference from where to start testing under trial and error as correct engine/transom height match will depend entirely on boats bottom shape, tube diameter, correct pressure on air deck & tubes, brand engine used.
Try this simple guide :
-Inflate air deck and tubes to factory working parameteres, usually 3.0 PSI minimum and evenly for tubes, 12 PSI for air deck.
-Sit engine trimed so to have a perpendicular engine and anticav plate paralell to water level once sib is floating. Test on flat calm no wind water condition preferably.
-To ballance well sib, sit a mate at bow, driver must seat on air deck next to transom. Use your kill cord and hold tiller firmly to go on a straight water course when at wot.
-Check water flow passing at speed through lower leg. Ideal water flow height to have excellent hole shot, superb tight turns and good top speed is achieved when flow passes slightly under small upper deflector plate.
By visually checking this flow issue, will know for sure if in need to raise the engine and by how much if needed. Test with different wooden shims thickness untill you achieve the described sweet engine/transom height match position.
Check this video for clear understanding :