1969 Arenacraft prop questions...

...I am trying to select a prop for a boat I just picked up. It's a 1969 Arenacraft with a 352 Interceptor (250HP), 1:1 velvet drive, a freshly tuned mallory single point, a Weber 600CFM freshly set up, and a new-old-stock 13X13 prop with virtually no cupping. No idea what the boat weighs. I get 26MPH @ 4200 @ 6000 feet elevation at 2/3 throttle. That sounds like it's set up for skiing and wakeboarding. I want efficiency and higher top speed. A prop slip calculator indicated .49 which seems pretty crappy to me. I am curious if these new NiBrall ski props are way more efficient. Federal, Acme, and OJ all make versions of them- they have alot of cup and claim to really move alot of water. Back when I was propping my last 4 boats 15-20 years ago I would just get something close to what I wanted for cheap and have the local prop wizard cup and pitch it to what I wanted. I can't find any used 13X15 or 13X17 and dang the new ones are spendy. I'm curious as to if I had an old 13X17 would it be like a new 13X15. WOT will get me 5800RPM @ 34MPH so I know there is ALOT of speed to be gained. As you would expect I have all kinds of torque- what I want is top end. I have a spare 12X13 for towing and I'm going to have this 13X13 pitched and cupped to a 13X15. My question is if I get a new 13X16 NiBrall ski prop will it be a big improvement over the 13X15 I'm trying to put together? I would then have the equivalent of a 13, 15, and 17 pitch more or less. Any advice? Also anybody know where I might find a used 13X15 or 13X17? I've looked all over Google. Thanks in advance...

Re: 1969 Arenacraft prop questions...

Your better off posting in your original post it will bump up.
I can only speak generically on your setup. We need the details on the boat
weight ,size, bottom.You probably know better than I what pitch works for your boat.I've had a number of straight drive inboards over the years a 53 ChrisCraft 18ft about 1500 to 1800 lbs fast shaped bottom but not particilarly smooth,with a 105 HP flathead 6 Chris Craft motor 1:1 with a 3,600 rpm red line.It ran a prop something like a basic 13 X 13 never checked the speed but probably about 30-35 at 3,500 to 3,600 these boats all ran in the mid 30s good overall performance loaded or skiing. This was pretty close to sea level.
Your pretty high up but it sure seems to me even allowing for cupping you would need more than a 13 and should be running faster than 34. at 5,800.perhaps you should check your tach. Your motor surely could twist a 13 up pretty tight. but only 34?Your other prop sizes seem closer to normal but it would seem they would be higher pitch.
As I'm sure you know a modified prop is only as good as the tech who makes it and can be somewhat of a comprimise comepared to a factory prop.

Re: 1969 Arenacraft prop questions...

...thanks for the reply. I found out that the boat weighs 2000# and the designer calls it a hydro-conic semi-deep-vee and describes it as a sport runabout. Yes the tach is incorrect so I double checked it with my shop dwell meter and that's where I get 5800rpm...