Choosing a 4 blade prop

I finally have a new tach and can ask prop questions. I have an aluminum 3 blade 15x15 on a 1999 Evinrude 150 Ficht Ram that does 36 MPH at 5000 RPM. This is on a 19.5 foot 1988 Sunrunner that has had the I/O removed and the motor is on a pod that was added to the back of the boat. Because of this, the boat is off center. I have cured some of the porpising problem by adding smart tabs, but would still like to push the stern a little more out of the water. I have also read that 4 blade stainless props are a little better on gas and make for easier handling at slower speeds. Any suggestions as to what prop I should be putting on this motor?
Thanks

Re: Choosing a 4 blade prop

Tell us about the Sunrunner it must be a real load for a 19.5 boat to require a 15" prop and only 3 props smaller on the list here.The setup seems to be working really well at about a 6% slip.
As an I/O I think it was rated for 245 hp that would indicate your underpowered ,that may account for the relatively small prop.
al or ss the 4 blade is said to improve hole shot,a slight fuel savings, there usually stay on plane better at reduced throttle, should save fuel. A ss prop should have the best slip numbers but
your already better than typical assuming your specs are right.
I would assume the 150 and a bracket arent as heavy as a I/O setup.
Anyway a 4 blade may help your porpoising issue.
It is usually suggested to go down one inch in pitch when going to a 4 from a 3.

Re: Choosing a 4 blade prop

Here is a link to a thread in this forum with a pic of the boat (had some input from you ). http://forums.iboats.com/showthread.php?t=505723 . I am not sure how the weight of the motor compares but it definitely changes the center of balance. The pod is aluminum and I would guess it to be around 80 lbs.

Re: Choosing a 4 blade prop

One thing I see in poking around for a 4 blade prop is that the smallest pitch (at least on this and one other site that I am looking at) is 15". If I should be going down 1 inch in pitch, does that make going to a 4 blade something I shouldn't do?