I"m running number 3 drives. Todate I have had her up to 72 mph on gps but the carbs are way out and I think the props are all wrong . I am hoping to see another 8 to 10 mph by the time she is dialed in.
RG.

Sweet rides...all of 'em !

What props and pitches?

Rick the boat looks good I hope to have mine in the water next year I just didnt have any time this year to work on it but winter is coming

Coolmedown I am running 25 pitch 4 blade clevers. Thanks Jay the boat in that picture has a scum line I should have washed off. I will take some shots of the bilge and new interior this weekend.
Rick G.

Assuming you have a 1.5 gear ratio in the drives, and the engines will make in the 700-750 hp range, you probably should start with a 28-29 pitch 4 blades. Just speaking from what I've learned from other similar 38 cigs.

Very nice. Best wishes...

10X you are right on with HP and ratio . I was thinking 27 to 28 pitch. Good to know I wasn't that far off. All input is appreciated, it is my first cigarette so I am still learning as I go . First boat was a 302 Formula, second a 43 Scarab and now this one. Three completely different rides and learning experiences.
RG.

just make shure u get 17.5 diameter props when starting to dial in ...i say 17.5 X 28 12 degree rake merc 4 blades is your ticket !

Im running 600 H.P. Roller Motors, Bassett Exhaust and with my 23 pitch marage 3 blades I can see 70-72 at WOT 5300-5400 rpm. When I put my Hydramotive 4 blades I hit only 65-67 at 4600-4700 rpm I cannot get it to spin more than that. The Nice part is the crusing Speed at 3200-3700 rpm with the 4 blades I dont care about top end The boat sounds like its running a 100MPH at 4000 RPM. This is the first boat I have never had some one run up on me to race them Weird. Or mabe Lake Saint Clair is always a 3-5 foot chop and the 30 footers and under cannot handle it.