That makes sense. I was hoping to get 120 out of my set up with 800's, but if I have to turn the wick up I guess that is a possibility. I'm dumping off some weight without compromising the cabin (that my wife must have) so I guess we will see.

remember you are a older hull and you are not running #6 drives those speeds would be 2004 and newer hull

Keep us updated on your build! Might as well go for 900-1100 hp and enjoy! Love those arnies!

Unless the Arneson's are significantly faster than 6's (which I'm not sure will be the case here), you'll need more than 800hp to run 120. Probably closer to 1000+. The older (early 2000's) staggered 900/6 boats generally ran in the 115 range give or take a couple mph depending on setup. 800hp will probably get you in the 105mph range (in normal running conditions with gear, fuel, people, etc).

I think you're right on the power. Regarding the difference between ASD's and Merc SSM #6's I think that the main difference will be the overall weight of the drives and power. I have yet to weigh my power VS. Mercury Racing power but I'm hoping to save 400 lbs. per side, and that is not including the weight deference in drives.

You would have to get those arneson,s way down deep and together to get the right attack angle, allot of glass work .

I had a early 2000 42' stagger 900 boat that ran 115ish . Know of a late 90's stagger stepped 42' with 950's that went around 110 . Both set up at the factory for big power with 6's . Not sure what power the Arneson #7 drive can handle HP wise , you may want to check into that first . Hope this helps , good luck with your projects

Im guessing you're gonna need quite a bit more than 800hp a side to get 120mph out of a 98 Step boat....IMO. I am currently running 1000+hp YPM motors. Best speed the boat ever saw was 122mph...but that was with IMCO SCX Toaster Oven shaped lowers.....lol.

Sixes are going on the boat now.....we shall see. Im guessing 130mph.....tops. Boat is an 05 hull and has been totally re-rigged/blueprinted by R3 and crew @ RF. FWIW......

Good Luck!!