I moved my boat forward on the trailer to get the balance so that there was more weight on the tongue. My boards on the trailer stick out about 20" past the transom on the hull near the rear of the bracket. I also always prop up the motor about 10-25 degress with a short cut board to keep my tilt and trim from getting damaged. I raise the motor and insert the board between the clamp and then run it down till it presses and the trim motor makes a binding sound. It keeps the lower unit off the road and keeps me from having to raise the motor all the way up on the factory support bracket. Using the factor fold out support tilts the motor almost 90 degrees out and hangs the weight on the bracket differently with the leg so far out behind it. Plus fuel left in the crank case drains out on the bracket sometimes at full tilt up also. I have always trailered with at board jammed in my trim clamp long as I can remember, My grandfather taught me this when I was 18 to save the trim unit, I have done it ever since.
