I have to lab my prop to see what will happen. Out of the box, the boat would hit 70 @ 5000rpm, then with muffs and broken in it hit 70 @ 4800+rpm. Once I do the prop, I'll take the muffs off and see what difference it makes.

Honestly, I don't feel any difference except the lack of stress when I launch and run in Havazoo.

Well there's something to be said for that! Do you have props for Tahoe? You'll need a smaller wheel.

No extra props for Tahoe. How bad will I have it with an EFI?

Should be ok but you're gonna' come up short without props. It's 5000' so the air is pretty thin. If you've never run there before stay well clear of the shore unless you're in a marked channel. There are some pretty big sharks down there and you won't see them untill you're on top of them. The water's so clear yoiu just can't tell how deep it is.

No extra props for Tahoe. How bad will I have it with an EFI?

20 years ago, I used to run west of Camp Richardson. It is incredibly scary when you go over rocks that seem to be near the surface. The water is so clear, they are actually 20-30 feet below the surface!

I think Powell is about 3700ft? Anyhow it's a HUGE difference. Maybe four or five hundred rpm difference (maybe more), you will need a smaller wheel, EFI will just adjust your fuel mixture for you, you still can't make the same HP that you can at sea level.

I agree, it'll be a pig at Tahoe without smaller wheels.

Lofty,
What other muffler brands have you tried before going with the GGB's? It is helpful to see other real world tests for comparision info.

Rick

Now forgive my ignorance for I am not a motorhead. When you say wheels, do you mean pullys?