Do you have a standard length lower or -2? Either way you could run a spacer and drop your current lower down instead of replacing....might simply be too high of propshaft height making it slip. Just a thought.

Also to your logic earlier....chine walk does not mean it's on the pad....you will know when its on the pad..the whole boat will lift and feel much more free and yes it can chine walk however it can chine walk just as easy not on the pad.

A 5 blade...maximus, max 5, hydromotive whatever you choose could and would probably help.

FWIW I'm going through this on my 28 nordic but mine is becoming more of a having trouble carrying the bow and not so much a slip issue however they both are related....mine has a heavy big nose whereas yours doesn't so I suspect if you have a -2 on it that's your problem and a spacer will help...the guys with stepped nordic heats which is more similar to your boat found that they had super high x dimensions and -2 shorty lowers hurt performance drastically and even a spacer lower than stock helped those boats....just another thought

How deep is the prop shaft in relation to the bottom ? trimming 4 4.5 ? Id take a look at the drive in that position you may over trimming

If the X dim is 18.5, then the propshaft would be about 3.25" below the bottom with a standard length lower.
X Dim/crankshaft center to Prop shaft center is about 21.8 inches
I would install a 1" spacer.

Thanks Griff. I actually used your method from a 2008 post on measuring x dim. Measure from bottom of hull to transom assembly and added 9.25”.

Are you thinking to reduce slip by getting more water to the prop or stern lift etc.?

i,m pretty sure reggie used a left rotation prop to help with torque not sure if it helped or was a gimmick

I’ve got a LH on it now so must’ve been a gimmick lol

I tried a set of Hydromotive's on my twin 35 (non-step) a couple of years ago. I could not believe how good the boat tracked, turned and top speed was better than anything. Bad news was it would fall off plane at around 33MPH. Took them back to the shop to see if he could fix the low speed falling off plane. Nope, settled for Bravo 1's.

Couple of things. First, do you have a drive shower installed? I would remove it if so for any prop testing as some of them can cause cavitation
Secondly, I have been where you are at a couple of times with slip #s in the low 20's. These were on boats that ran around 75mph and I was trying to get to 80+. You probably have a faster hull than mine were, think West Coast stuff. A 5 blade or a drive spacer will most likely lower your slip and possibly pick up some mph. But not all slip is bad slip. Think of the Bravo drive as the 10 bolt chevy of drives. At some point you will get the drive hooked up too hard and it will self destruct. Once when I added a spacer I lowered the slip dramatically and picked up 5-7mph instantly, for about 5 miles until the nearly brand new XR ate itself. This was with about 730hp@82mph.

I would start with some prop testing and then move on to spacers 1/2" at a time. Some times it doesn't take much.

Putting the prop deeper will get it to cleaner water and allow it to carry the bow better due to more bite and leverage.
My 28 Pantera had a notched transom and was cut at 20.5 and had a 2" spacer, making the PS depth the same as an 18.5. Slip% was high like yours and trim had little effect on trying to raise the bow. I changed to a 3" spacer and prop slip went down about 7-8% and responded to trim much better. Being you have a steeped hull, your boat is designed to run flatter, but you still only want about a foot of water contact in front of the step.