I agree there is minimal gain to go thru all that work. I’ll live with the fact that I have to
bring it up to 3500 to get on plane.

LOL. Yes. It's on a lift so it makes it more difficult to check out. I had to borrow a friend's small floating dock to get to it.

That's my rpms too. Lots of bow rise still and fairly slow to plane out. I already put on a Max Machine Worx cavitation plate and run a 5 blade. Next I'll have to look into a 1" driver spacer.

Do you have trim tabs? You can drop a little tab to get you on plane then pull them back up...that way you don't lose anything on the top end with spacers and what not...I believe in this situation the five blade may be hurting you...might be biting too hard initially causing the bow to rise and then doesn't have enough to make it fall over....could be way off but a possible lab job on the prop from a reputable source may solve your issue...just some thoughts before you start going down a rabbit hole of endless parts and time.

Stewart

I think my problem is my x dimension is high. The shafts are 3” below the bottom. I’ve tried my tabs in all location and the only way that helps a little is all the way down. I have 280 tabs and was thinking the longer 380 tabs my help. If I find a set of 380 plates I’ll buy them and give it a shot.

Was just a suggestion...that's weird about your 280's..I put 280's on mine when I did my refit and if I bump those things at all down you can feel it! Granted I only have a 28 nordic heat but they make a world of difference for me. I believe hardin marine sells a kit to upgrade 280's to 380's I think. May be worth a look

Stewart

I have a 30 Cig Mystique Twin Step

Where are you tabs located on the boat? Mine are as wide as I could get them on the back and the hinge pin is about an inch above the bottom of the boat. Yours isn't that much bigger than mine and its crazy to me seeing what mine do that your 280's don't bury the nose of that thing when down. If I drop mine like an inch below the bottom it physically lifts the back of the boat and buries the nose. Your boat is heavier with a deeper vee and twins in the back so I'm sure all of that comes into play however. Plus you're stepped and mines not so that plays in a little too.

Stewart

A simple mod for negative trim is running the "celery stick" in the rearward position.