And yes you are just as bad!!!!!!

I think you'll need bigger than 26's with over 500hp.. I would run 4 blades though better cruise and economy may be a touch slower at wot with them but not much..

My neighbor has a 91 280ES with twin 454 mags and just over 1000 hrs on them. His boat does a honest 70mph on my gps next to him and his boat was full of fuel, 4 people, coolers, etc.

I was impressed with the speed given hours on boat and all weight in it.

I helped a friend on a 280, installa set of 502 making about 600 hp and it did right at 80 with 26 pitch bravo ones. Invest in kplanes and some bottom work. It was ok but after 70 it would dance a lot. This was on a GPS did have full hydro steering, IMO Absolutly necessary at that speed. When it had 330 hp it was running 23 mirage plus and with 400 hp I think it had 24 pitch four blades don't remember what brand. I helped do a lot of work on it and was in it a lot.

Shorty drives do wonders on these hulls
I don't know that a 4 blade will help all that much. More blades = less slip. But when the propshaft is almost 10" below the hull! 3 blades don't slip much! (10 is an exaggeration)
I took a 292 formula out yesterday, similar setup, cruised at 55mph GPS @ 4000 rpm with 25 mirage plus 3 blades that have been "worked" by river debris lol

Need to decide where the pocket books will take you...my friend had invested a lot more than originally planned for the new motors and his would cruise at 50 and about 3000 maybe a little less rpm, that was the best part of the bigger hp motors. Don't get me wrong it was an awesome feeling at 75 + but he was not wanting to spend the money for a blueprint and big tabs. If your not running wot it felt great

Agreed!! My cruise went up substantially with my bigger motors. You don't run wot all day, I want the better cruise speed over wot any day of the week..

Well.....what ever became of this?

Ran 27 mirage plus, only got to run it up to 5200 a few times after breakin and then I blew a head gasket due to a head bolt tearing out of the block. Looking for a .030 over block now, that block has seen to many years of salt water. She ran 78 and had more but I (for the first time in my life) didn't want to run hard and hurt something. I just bought a pair of 27's that have the tip mod done so I'm hoping I'll see 80-82

Ran 81 on GPS today at 4950 with the new props (I guess the 4-5mph gain they advertise is true less slip also) Low fuel psi. on one motor, new pump will be here in the morning, hoping to spin her up to 5300 and should see 85-87. She likes the cold air and lives to chine walk!!!!!