Recently added 4 inch spacers for a total of 10 inches of set back, removed the wedges, replaced the seastar steering cylinder with a uflex cylinder, added Allison's CMC upgrade kit. Was running a 29 pitch XOB with a full flare. Motor is 250 with 1.62 gears. 3/4 tank of fuel and my normal tournament load. Air temp was 50 degrees, didn't catch the water temp.
Learned 4 things, 1. The 21 foot boat was made for 10 inches of set back, even removing the wedges the 2 additional inches improved my hole shot, drive, and made the bow lift much more responsive. 2. The CMC upgrade kit takes the slop out of the plate, no more side to side movement. That's assuming your rollers aren't worn. 3. The uflex is tighter, stronger, more responsive, and doesn't have the spongy feel my seastar had. It turned effortlessly even at 90. I realized after several runs I hadn't even thought about the drive/steering. 4. I also tested a 22 pitch unvented bravo 1 I bought to pull my grandsons on a tube. As expected the hole shot was stupid good, and up to 60 mph it was serious fun. This blew my mind, I was able to run as low as 12 mph without any porpoise at all. Tucked the motor and ran the plate all the way down and it just settle in very stable, could not believe it. The 2 inches of additional setback made a huge difference on the bottom end. Able to stay on plane at 18, very stable.
Very pleased with the upgrades, well worth the time and money. I didn't get to stretch it due to cross wind gusts. The 1 time I did stand in it, it climbed through 91 fast and was still digging when a gust changed my direction.