Improvements for 575sci's
 

What could I do to get more power from stock 575's and still stay reliable?

Nice set up! I have seen 575's with inner cooler added along with pulley change and ECM reprogram. Not exactly sure how much HP was gained. Depend on final boost setup. I think they are pretty mild tune as they come from Mercury. As you know more HP means more frequent rebuilds but a lot depends on how hard you run or constantly push those sticks WOT! :D

How many hours before first rebuild is due?

We dropped down to a 4" blower pulley on our 575's. It increases boost to ~6lbs and you'll see a small increase in HP. I've been told by our mechanic anywhere from 50-75hp increase. Although with our engines, it feels like it's probably closer or below the lower end of the range. You'll notice better acceleration plus a few mph on the top end. You may hit the rev-limiter so it may be necessary to change props and/or recalibrate your ECMs. We ran the boat hard all last summer and had no problems.

If you're interested in an intercooler--bigger HP 700+ (plus lots more $$$$) check out PFM http://www.superchiller.com/pages/575MCSci.html

Check out Spine Tickler in the Classifieds for a picture after the changes. Whipple Intercooler, pully change, upgraded head gaskets and ECU reprogram. Probably around a 80-90 HP increase and very reliable. 91 mph best before the modifications and 97 mph after. No hatch changes with only a 1.5" increase in height. Runs awsome with no regrets.

Thanks for the great info guys!!