boat mods this spring i completed my project boat up grade i have a 21.5 chriscraft fishingboat it is walk around the specs are app 4000#1.5 outdrive 454 mercruiser thru out drive exhaust torque in ft lbs 448.9 at 3600 rpm hp is370.6 at4800 rpm crank specs are higher i think the specs listed are correct to use i seek help in prop selection as well as app top speed thanks for any info you can supply thanks racoon2us specs are dyno specs

Start With A 21p 3 Blade Then A 23p