Prop for a 16ft bow rider

Hi i have a weird set up its a merc 140 and a volvo 270 leg im not sure what prop pitch i have but i know its to much i think its like 21 or 19 the boat its self is a 1975 chriscraft crest trihull bow rider now i haven't really pushed it but i know i cant gain 1000 rpms with the very little throttle i have left to go so i would say it tops out at around 3600 rpms i will find out for sure on fri but i know its not a spun prop because it had just been repaired at the prop shop b4 i bought it. so what suggestions should i look at if its a 19 should i drop down to a 15 or 17 and vice versa. the wot for this engine is 42-4600. all help and links are appreciated.

p.s. i will def be replacing regardless once i get used to trailering this boat already hit the prop once lucky no Major damage lol

Re: Prop for a 16ft bow rider

Please read "read this first" at the top of the page.get us as much info as possible.So we can evaluate your setup.
Do you know the gear ratio on the leg?May be on a tag on the upper gearbox.You don't say what size the boat is?
You can't really make up 1000 rpm with a prop starting from a a 19 or 21" prop.That would put you at about 14 or 16"
A size you would usually need for a pontoon or other hard to push boat.You might us a 16 for heavy water sports but would normally have to watch not to over rev.Your gear ratio may be wrong or you have issues with the motor or setup.