I run a 26P Bravo1 on my 29 single 500EFI thats what it came with per the factory report. Seems to be fine but I usually only have 2 people and avarage gear. I think it planes fairly well, although I have seen some plane quicker.

I tried a Bravo 1 26P prop the other weekend, and hole shot definitetly improved. However I lost 10 mph top speed. Boat would do high 70s with the 28P and high 60s with the 26P. Not worth the trade off - time to go back to the 28P.

I agree with you there. My 27 is a dog to get on plane, (with a load in the boat) but the top speed is worth the trade off.
People call them "go fast" boats all the time....I've never heard one refered to as a "get on plane" boat!

Something is up...

You should be able to run high 70's to 80 mph with a 26P.

Where is your trim & tabs?

You should see this with a 28P:

And you should see this with a 26P:

Maybe there's a hook in your hull.
Maybe you're way loaded down.

Trim at 4-4.5 WOT, tabs at 2...

No water in the tank, 2 people, 60-80 gallons of fuel...

Let's figure this out...

I have been slowly figuring out how to get our 1995 27 on plane and going it has a 502EFI mag with a procharger it has a XR out drive with a merc 4 blade 30P on it. It is a dog out of the hole but once it gets going hang on. The guy we got it off of stated that it was a mid 80 mph boat does that sound about right? Just playing around with it I have seen 75 but didn't really want to push it too hard being as we had just got it.

Is the trim adjustment insert installed for full negative trim of the drive?
Alot of manufactures set them up in the safe position to reduce the chances of spinout.

UM not for sure
 

Sorry you lost me. When the out drive is all the way down the needle reads 1 when the needle reads 6 that is as far as the rotary trim buttons will take it, you then have to use the one on the dash to achieve "Trailer", Hope that is what you are asking.

Once it starts to come on plane I think it starts to slip the prop pretty bad really have to pull the stick back.

Where the trim cylinders mount to the back of the drive there is a plastic insert. It can be installed in the front or rear position. Keeps the drive from tucking full under. Its also known as the "celery stick", It will not show on a mech trim indicator which position it was installed. Formula also does this to all their boats that we've seen. For people that don't know how to trim, this keeps the drive slightly out so there is less chance of spinout during turns. Part #30 in this exploded view.