Thanks for contributing! I hope this thread can continue to build, and help people out who are looking to upgrade, rather than having 20 people speculating about what will work. I realized I can add another boat to this; my father in law has an '89 Comp with an Acme 1868, which is the same prop as mine but his boat is quite a bit different.

1989 Supra Comp

Engine:
PCM 351W ~240hp (bone stock, approx. 900 hours)
1.23:1 transmission
Acme 1868 Prop: 12.5x14.25 4-blade .075 cup

Performance / Usage:
4300 RPM WOT with no ballast / no passengers. ~44 mph although I have not GPS verified this.

This boat is basically a cruiser and almost never used for skiing, and never runs any ballast, ever. Usually 1-3 people on board. It has great hole shot, and fantastic throttle response throughout the RPM range.