Have had twin engine boats for 15 years,,Here's the odd thing.. I can have 1 person or 4 people, 1/8 tank of fuel or 3/4 tank.. Max speed is always the same 73,2-73.5, I have tried every trim angle, some K-planes, no planes, more trim/less you name it.. I think my prop slip is too high. I have a set of Bravo 28 and max speed is the same on those, I get more RPM and on plane quicker but same speed...
I guess I'll be selling my labbed 30's and my 28's to buy a good five blade F+++$$

How about a slightly different angle, you'll need camo gear and late night access to your buddies boat to retard his timing a few degrees... Taken straight from the book of "If you can't beat them honestly- CHEAT!.":lolhit:

Ok, now back to the helpful hints.

Guy has 454's.

How deep are your props sitting? Even with relatively high x numbers your B1's should work. If running 1.65's I won't say your lab job is bad, it was only if running 1.5. Nothing against Bblades. It's all good.
Just curious. What is Brett saying about your 17% slip? If I was you, I would talk to him about the QIV, P5, Hering 5 blades and the maximus. In other words, what you said youself. The 5 blade options or the QIV.
I know this might sound off, but maybe a ½" spacer could work too. Spacers does not always rob speed you know.

in my experience all lab props do for me is slip more I have never gotten more speed out of them. I agree that there may be some speed left in playing with the x-dimension. You are doing pretty good keeping up with boat with 502's your mods must have got you up to the 415HP mark.

Stepped hulls are not AS trim sensitive as a traditional vee, but trim angle and weight load should still certainly have a very noticeable effect.

If your props have been worked by somebody, then you need to get real life slip numbers on both sets of props and tell the guy you need more bite, etc. A good prop guy can hammer whatever you need into them. Sometimes a little more cup is all you need, other times it requires something more dramatic.

MC

I do too. The 496 exhaust bolts right up to the 454s - no problems. Been there, done that.

nose cones
 

I thought about nose cones,, Some say "no" unless your doing 70+ others say 80.. MAyby it will allow the water to feed the props better.. Problem is once you get them on I imagine it sucks taking them off..

You might want to check your plugs try going to a little colder
plug, bump timing up 1 or 2 degrees.
From your info,sounds like you need a prop rework.You might need more bow lift or more stern lift.
Have someone record your boat running at wide open throttle
from alongside to see how much wetted surface is in the water
When talking to your prop shop,the more info you can give them the better the end result.
To get 2 MPH look to the prop.

correct slip
 

In theroy if I could get 11% slip then I would be running 80..
But I think when you run a 5 blade you drop pitch,, thus speed but more than I have now..WTH,, This sucks.:grinser010:

Well, it does not really work like that. You will also loose some rpm's. If you can get your slip down to 11%, the 2-3 mph range should be within reach. But yes, start at the prop. I seriously doubt that a nosecone will give you anything. It will make your prop hook up more, but it will also create drag. Speed wise, you are nowhere near blowout due to speed and gearcase torpedo length.