Great ideaShim it and clamp it. Don’t run but just a short run. Check clamps and run again. I have told many people not to run their motors only clamped on, but for tuning it is acceptable as long as you are mindful and smart about it. Take a scrap 2x4 and cut 1/4” shims with a table saw then go to the water. I have done this more times than I care to remember!