Re: Sx19
Hey Craig, welcome to iboats.
Just about everybody here is going to say, "SKIP THE FOUR CYLINDER", but that is the easy thing to do when it is somebody elses money. While 19' is really pushing the limit for a 3.0, with the right prop it will pull skiiers and tubers with no problem. Where low power really hurts you is in top speed, I wouldn't expect much over 40mph, Which if you have never had a boat, it feels much faster than 40mph in your car.
The 4.3 will probably push that boat in the mid to upper 40's jump on plane slightly quicker and the difference in cruising economy should be negligible. However, you are looking at an extra 2k upfront.
Bottom line, you need to sea trial the boat before you buy it. It is the only way to know if will do what you want it to.
Good luck.