I had the opportunity to run Hydro-Tec's Yamaha SHO Modded gear case this past weekend i ran it vs the 1.62 Sportmaster back to back same day same conditions same prop....Most noticeable was the water pressure/cooling..... The sportmaster I have been running for several years now and it has it quirks with holding pressure and cooling the big yamaha.... its fairly often when surfacing the prop/gearcase it will drop pressure and hit guardian/hot alarm and it does it fairly easily...with Hydro-Tecs Modded Yamaha case it cools much better I didn't hit guardian at all even when I dropped the pressure to less than 5lbs still no overheat.....the sportmaster will hit guardian at 10-12lbs...Top speeds were nearly identical with the biggest improvements in handling and engine cooling and of course the annoying sportmaster gear clunk when it slams into gear....Yamaha cases don't do this.