Hi I'm looking at an 42 post, with vt 903 I assume 400 hp or maybe 425 . I wonder, what kind of speed this boat should run, its an 1975 . I searched but can't find any information, maybe the folks here know more .
Keep looking. A mid to late 60s design. Designed to compete with 8V71s. A poor attempt at it anyway. As all old Cummins Vs, keep on walking. There are better boats to sink your money in, including 8V71 powered ships.
If you really like the ship and want a keeper, re-power as soon as you can. Newer horse power is a fraction of the weight. Again, if it's a keeper.