25 Mirage Plus, and prop for 5500-5600 rpms with a normal load of fuel and folks. You would probably need to have the 25 labbed to get your rpms high enough.

Personally I would go with a four blade like a 24 Bravo or maybe a 23 Rev4. My rig, though bigger, runs the exact same speed as Mirage Plusses with Rev4s and handles much better. I found the same results when I tested props on my 22 Whaler, the Rev4 ran just as fast as the three blades.

The more I think about it the more I think the 23 Rev4 would be perfect for you. I hit 71 at 5300 rpms with decent slip numbers with 23" Rev4s

I have heard that the 242 handles bad with a 4 blade. I'll have to play with it.

I will ask endeavor2 what he ran for prop on his. He had a hopped up worked over 427 in his. Will have him post what prop worked at higher speeds etc,

The guy that put the bbc bravo in my boat, claimed 78mph with 630hp. No idea what props though.

I bought a 25p mirage plus today. I'll let y'all know in a week or so how everything works together.

I was gonna say run the 23 and see what you have before buying anything else. but the 25 is a good middle if the road prop that can always be re-sold...and 2 to compare also will make the first couple of runs more fun.

I'd say to prop it for around 5500 based on the cam. Not sure how much you're overdriving the blower though.
You really don't want to spin the 177 more than about 12000 rpm blower speed. I think max rating is 13500 rpms for the blower, but that really creates some heat.

I am spinning the blower 2:1. So that would be 11000rpm max.

You don't want to lift the stern on a 242 and a 4 blade will do that. I tried a pair of 4 blade 22" on my 255 and it was squirmy once it planed out....the boat wanted to dart around like a top water Bass Lure!! LOL

Sounds like it's going to be fun !! Make sure you have a Kill Switch and Lanyard !! LOL