4 Blade SS Prop?

[TooFly]

So I took my new-to-me 20'er for its first (12 hour) spin last Wednesday and absolutely LOVED it. I've been in a few boats over recent years and have to say that, aside from the wetness due to self-bailing issues, it's the nicest ride I've experienced in an 18-22'er. IMHO, the ride is even softer than my buddy's 22' Hydrasport (kevlar hull) in up to a 2' chop. I told him that.

My concern, ATM, is getting up on plane. With two of us onboard, a bunch of fishing gear and tackle (~ 60 lbs.) moved forward and 50 gallons of gas, I can't get on plane until I hit 18 mph. Here are the stats:

20' CC with a Gil Brackett (2' long)
150 Evinrude E-TEC
14 3/4 x 16 Viper 3 Blade Lefthand () SS Prop
32 mph @ 4200 RPM
38 mph @ 5000 RPM

I haven't gone above 5000 RPMs, yet.

Will a 4 blade prop make a discernable difference with getting up on plane at a lower speed? Will I lose a ton on the top end? I'm debating a Cyclone 4 Blade lefty SS prop. Can anyone recommend the right size prop? A couple shops (believe it or not) seem iffy on the subject.

Thanks,
Paul