B3's or B2's

[capttom1]

I purchased a new 1996 CC25 and have enjoyed ever minute on the boat. I’ve had my share of minor problems such as replacing the horns, windshield wipers and etc, but in the past several years the engine has been an issue. I had to do a whole top end job on the engine two years ago after I discovered two broken valve rods. The mechanic said it was due to rust. My top end wide open is only 3500rpm and maybe 29mph. after going to the NY boat show last night and speaking to a Volvo representative he said to drop down a prop size and have a compression test performed. He wants me to drop down from B5’s to B4’s. Any suggestions?
Tom