Re-bunking.
Ken,I had really good luck with re-bunking. I measured the distance between the two bunks, then placed a 2x4 under the keel and supported it on both sides and leveled it. This way I was able to measure the distance between the bottom of the (retracted) keel and the bunks, from this I derived how high the bunks must be in relation to the keel. I was able to transfer this measurement to the new trailer and set the bunk risers accordingly. Keep in mind that the bunks will bend in the middle (as they should to hug the hull shape). I added an extra four inches to account for this too.When I finished that part, I took it to the boat ramp and floated the boat on a rainy day (less competition for the ramp). I was lucky enough to hit it perfectly on the first try. I've since adjusted the front of the bunks down by two inches and the back up by 2 inches. This just facilitates getting the boat on the trailer easily.I lucked out with the width of the trailer, I hadn't really given it much thought, but my V21 sits perfectly between the wheel fenders. This would also be an important measurement. Good Luck..-=gp=-.