Try a Rev 4, I run that on my 91 242 SS with the 365 Mag. Loose a little top end speed, but really makes a difference in all other aspects of performance such as hole shot, cruise speed, and I found I use less trim tabs overall.

couldnt agree more with Solan Goose..... running a turning point 4 blade 14 1/2 21P. always got a load of people, fuel and coolers, comes out of the hole great, cruise speed is awesome turning 4500-4600(a little low but not concerned) 3 blade gave me a few more mph on top but i dont run around wot all day.

What kind of top speeds are we looking at with the 4 blade?

My boat has the 7.4 Mag. Stock motor, but I do have the Gill exhaust. Best I ever saw with my Rev 4 19 pitch was 57, and best I got with my Mirage 21 pitch, which was the stock prop was 60. Those are GPS numbers, not boat speedo. I would say, expect to see 2-3 mph decrease with the Rev 4. Whatever prop you currently have on the boat, drop down 2 pitch sizes with a 4 blade. Neither of my props are Labbed........yet.