[RI Tiara]

I have a 1987 3300 flybridge with 454 crusaders and I have a dilemna. Original factory test sheet shows 18x19x3 blade props and the performance figures look spot on. When I bought the boat it had 18x21x4 blades on it (for the 8 years the previous owner had it). So an additional blade AND more pitch doesn't seem right to me. Handles and cruises nice but won't pull past 3800 (thats low), tops out about 30mph (seems OK), and seems a little down on mileage. I'm thinking I need to reprop to similar as from the factory. I run the boat at a steady cruise between 2800 and 3100. At 3000 she cruises about 22-24mph. No delusions that this is a fast or fuel efficient boat but I am wondering if a re-prop is worth it. These figures are similar at cruise to those I have seen others post when selling similar boats. No expertise in this area! Suggestions?