That sounds like a close comparason to my set up with 700's with SSM3 running 76-77 gps, thing is like a tank in the water! Wish it was faster with that kind of power but its reliable power and I can handle mid 70's with this beast:)

I have an article from powerboat magazine where they tested a new 1994 Straight bottom 42, equipped with the 800sc #6 package. Boat did 84mph on radar with that package. That was a new boat tested in saltwater. I'd imagine it was a 80-81 mph boat in freshwater with normal gear on board. I think the 600sc setup would run mid-upper 70s.

Maybe I need to double check with the speed of my 42 . It seems like 88mph with my current setup is impossible. Guess I will try it out this weekend

I would agree with this "I think the 600sc setup would run mid-upper 70s". I had a 90 42 with factory 420's turned into 525 SC's with TRS that would run 72mph.

1990 42 ft 540cu in 10-71 blowers 7 lb boost,805 hp at 5400 with konrad drives 30 pitch bravo ones spinning in best.83mph,5 blade maximus no lab 85 mph,takes a lot of power to get these old tubs up and running,but I love the rough water ride

I know it's not a 42, but my straight bottom 38 Fever, blown 468's, SSM IV drives, 88mph. Engines made 800hp on dyno at 6000rpm , 760hp at 5500. Right now I turn about 5500-5700 with props I have. I think with some prop tuning and what not it will hit 90. They are tanks. Mine with no fuel on trailer weighed 13000 lbs. Full fuel over 14,000 on trailer