I realize this is a super old post but I'm looking for tips on aluminum angle measurement... I need to build this jack plate on a 10ft aluminum rowboat with a 15in transom and the motor I need to raise is a LS 6hp (55lbs) somehow measured 22 inches from cav to top of transom mount.... I need to get the motor up 7 inches(ish). Can I still copy this build and raise it 7 inches or should I cut my angle longer? Firecat recommended 9 inches under the transom for support but his motor was a lot heavier than mine which is why I'm wondering if I can get away with just 5 below the top or the transom and 7 over. Thanks.