Zero chine walk at any speed running 12-14% slip depending on conditions at WOT.

Your slip seems high. I am running a labbed 30 Bravo 4 blade, 1 inch above the lowest point on the hull. No box at test time. Installing this week. And I got 11% slip from 4000 to 6000 RPM. at 93 MPH. 650 HP
You measured your prop shaft height as 1/2 inch above the center pod. what is the height above the lowest point on your hull. Run a straight edge across the back of the hull from side to side. If it has a cut out like the Daytona's have then go forward of the notch.

On the AO the center pod is deeper than the sponsons at the transom. Not much but deeper nonetheless. I'm really happy with the performance. WOT has the engine spinning between 5600-5800 RPMs. That is where the engine makes peak HP. The GPS speedo only goes to 100mph. I think I'm running somewhere between 100-105 depending on the conditions. I had the drive deeper in the water with a larger spacer. The slip was in the single digits but it wasn't as fast (mid 90s at 5400 RPMs). Good luck with the install of the box. Let us know how she performs.

Who designed the 26 American Offshore originally, maybe better question is who is a guru for the right setup? I was told one went 130's at LOTO Shootout!

Tinkerer- I was the original owner of your 26 Daytona, but not the 2nd Owner, who let it deteriorate. I ordered that boat, motor delete, drive delete and received it in Fall of 2000, many great times on that hull! Teddy told me what you have been doing with it, keep us posted on the details of the setup.

I believe the 26 AO bottom design is a copy of the 25 Talon owned by Hustler. I'm not sure it's as fast as a lot of modern single engine cat designs because of the large size of its center pod (doesn't pack as much air). However it leans in on slow turns like a V and has a really nice ride all over the operating range. I spoke with Art DiNick (multiple LOTO Shootout Class Winner with 31 AO) about the setup of my boat w/ X dimension when using a box and he was very insightful.

Jspeeddemon - HE sure did let the boat go to hell. I have never seen a boat that was so badly neglected. What engine and drive did you have in the boat? What speed were you seeing? I am in the process of installing an IMCO neutral box, redoing the dash with a GPS speedo and all new gauges, I had the bottom repaired where the previous owner beat it up. Has all of the holes in the engine compartment filled and then AWLGRIPED. I am also building a 598 for the boat. This summer ( when I get it together ) it will be NA - this winter I am installing an M4 Procharger and a SCX -4 drive.
Anything interesting about this hull from when You bought it?

That sounds awesome, I'm glad someone is taking good care of it. Nothing that I can think of stands out. I had a Procharged M-4 setup in it myself, with an Max machine worx XR, it ran well in the high 1 teens. He put a 2 inch shorty on it, which it needed all along. That was worth some free MPH. Best he got it to go was 109, but he only had about 800Hp At 6000 Rpm.
Just bought a 26 American Offshore I'll keep you posted.

Tinkerer did you get the Eliminator going this Summer?

I got it on the water last summer with all of the new stuff except the M4 and -4 drive.
I am running the 598 NA at just over 800 HP, Imco neutral box and -3 drive. My prop shaft is 2 inches above the lowest point of the bottom.
I have had the boat to 112 with a stock bravo 28 at 6100 rpm, 1.34 drive ratio under ideal conditions.
Last weekend I had it at 110 at 6100 Rpm with almost full tanks but then blew 1/2 of a blade off an almost brand new labbed Bravo 28 prop.
This prop is 5 mph faster than the stock 28 that I finished the day with.
Under ideal conditions I believe it would have gone 115 to 117.