Who here has modified there top end and what power did you see with what combo? I have a 96 baja 20 outlaw with this engine and want to get in the 70's mph range with it.
If you have the Alpha outdrive, make sure you don't exceed the power rating for the outdrive. I had a 1989 Baja Force 216 which was a 20 foot boat with the same stock 5.7 liter with an Alpha drive and was able to hit 65 with GPS without any engine mods, so I'm sure you should be able to get to the 70's without a whole lot of additional power.