Correct prop size?

Good information, thanks to all. Funny, back in my I/O days I was a bit of a prop guru.... but the direct drive arena is a whole different ball game and I'm a little blind here.   

From what I've read already thanks to all of your google-fu suggestions, I've come to the conclusion that my prop, whether the pitch is ok or not, has got to go. So many posts talk about the old cast vs the newer CNC, specifically the consistency of the pitch and the balance of any individual blade. This is an area that I had never even considered as I had no idea the older props were cast - I had been used to dealing with props that were forged and balanced.   Ever since my first test drive I had noticed a slight, almost undetectable vibration that seemed to intensify the higher the rpm. I was hoping it wasn't a bearing somewhere, and all inspections seemed to confirm that as well. The prop imbalance would definitely account for this.

On another note, MrMcD's comment has me a bit confused...

MrMcD wrote: ... I understand the Acme 422 is the most popular size for this boat but my 224 works really well also.

In researching these two props, the 422 specifically states it has a 1" bore and the 224 says 1   1/8" -   Different bores available for different shafts? Adapters?

My 95 GT40 Pro Boss 310 HP Ski Nautique with an Acme 224 Prop will tack up to 52-5300 and will exceed 46 MPH.    32 MPH is taching more like 3400 RPM.
It used to pull 2-3 mph more but after an accident I had to have the prop straightened and it has not been the same since. Smooth and strong but I lost 2-3 MPH when the prop shop fixed my bent blade. I understand the Acme 422 is the most popular size for this boat but my 224 works really well also.

So.... numbers don't quite mesh.   PCM manual says the GT40 has a max rpm of 4800 and the 1995 CC brochures say the SN has a top speed around 46-47 MPH.   I've been noticing that my RPM's are somewhat high while cruising - at a comfortable 32-33 mph cruise and/ or ski speed the tach registers around 4000-4200. That doesn't give much room for getting anywhere close to 46 mph in the few hundred R's I have left. I haven't pushed it passed about 38-39 mph as yet, but at that the tach reads that I'm pushing 5200 or so.
Now first, I've always been very attentive to the engine and drive train with all my vehicles, boats included of course, and I'm fairly certain the engine isn't running at 5200 or even close - more like 4200 - 4400.    However that's still close enough to the top end that I have been wondering if the prop had been swapped out to a lower pitch at some point for some HD pulling power or something.    The other thing with CC's stated top speed is I can't find any info where it states which transmission ratio this is. They had 2 available: the 1/1   and the 1.23/1 - my SN is the latter.   Makes sense that if their #'s were from the 1/1 the top speed #'s for the 1.23/1 would be much lower.   So the question is how can I confirm that I have the correct prop for my transmission? If my ears are deceiving me and I really am cruising at that much higher RPM, I don't want to hurt my engine so I really want to get the correct prop. Checked the prop and the only markings on it were: