I have an 86 242 with 420hp bravo combo. It runs 63mph. The transom was rotted, and I am currently rebuilding. Would I gain any speed from raising my drive 2-3 inches? The only negative I could see was the hatch would be too close for a blower. Any info would be awesome.

what if you raise it 1 inch and then go with a shorty? then you can try 1 and 3 inch height change while having enough room at the top. and you can re-sell the drive you like least after seeing what works best...what was boat originally? TRS or small block alpha?

Find you a Blackhawk and set it up for that. that 242 will be a scooter with a properly set up hawk and some power. the one we ran for merc run a touch over 72 with a hawk and a stock 502 mag.

The boat was a 260 alpha boat.

I have a 84 223 with a 330hp sbc and an alpha ss. Personally I haven't noticed much of a benefit running with a shorter drive. With the alpha the boat consistently runs 49 to 50mph (gps) full of fuel. It may have picked up 1maybe 2mph with the shorter drive, although it did hit 54.9 (GPS) but I only saw that speed once. also the bow seems a little heavier in the water and requires more trim to get it up and The prop likes to leave the water much more often. hope this helps