Propeller problem!

my problem is in 2014 I bought a 1990 Baja 370es with twin stock mercruiser 454/425hp both engine are in excellent condition just rebuilt good compression etc.. this boat 10000 pounds without fuel, gear etc... it comes with hydromotive 22p 4p 15½ dia. but with these set up my max W.O.T is 4000 to 4200 rpm!! and run to average 52-53 mph. I know this boat are not offshore or very fast hull because it seems like (sport cruiser) but I like this boat! very confortable and smooth. but in my mercruiser ownwer's manual this engine w.o.t is 4800-5200 rpm. I need 600 to 1000 rpm gain!!,



some guy's tell me install mirage plus 21p 3p 14¾ dia but here to make a test I need to buy propeller! I want buy the right propeller!

mirage plus 21p/3p dia? or if you think I need other propeller make and size?



thanks for you support!

Propeller problem!