the way I see it, you are only 60 hp away from your goal. did you store your motor properly? does it spin over fine? if so, I wouldn't tear it down for 50-60 hp, I would do a cam with a good torque curve. what is your intake? ignition sety up?. losing the engine driven fan for an elecrtic helps a little. header choice long tube vs short. etc. Guess what I'm trying to say is that you don't have a lot of ground to cover to get your hp goal. what are you towing for a boat? hell I towed my 47 ford back 200 miles of hills with my 3.9 v6 dodge. was a little sluggish on some big hills but we never dropped under 50. I know your crate 290 hp probibly is around 275 or so on torque . one last note if you don't have one, put on an auxilery tranny coller. my 2 pennies