496 exhaust manifolds, SS intake and Inconel exhaust valves , pocket ported factory heads , comp cam springs, tie bar roller lifters, .218/.224 .51" lift. 9.0:1 compression, squish corrected, new rod , arp studs and bolts , remote oil filter and cooler 10AN lines, oil thermostat, fresh water cooling, forged 540 crank. Adjustable fuel pressure regulator, captains call exhaust. Mild build

Mirage + 23" is a great starting point.
Don't be misled into that math model you were looking at...25 - 30 mph at 3,000 rpm doesn't represent well what the hull will be like at higher speeds with less wetted surface. Looking at a common prop chart, if you can twist that 24" to 5,000 rpm you should see mid 60s at 15% slip.
https://cimg8.ibsrv.net/gimg/www.off...46a5208fa7.jpg

Comp says 5400 rpm

I’ll bet thst cam in a 540 mskes peak hp around 4500 rpm ? Or a tad less ? 218/224 is mild for a 350. Peak hp rpm 5200or so on the small 350.


454 mpi/ 502mpi is 224/224
500Efi is 230/236
525EFI is 236/ 244

I realize its a mild cam but I figure that it will make reasonable power, have a nice idle quality. If it doesn't work ill have to swap it out. Its easy to make a fast boat slow with bad cam choice

I’m justvreplying to post #13. Hope my info helps.

I'm sorry, I lied . It is a quicksilver 23p
https://cimg9.ibsrv.net/gimg/www.off...7897f4c6ba.jpg
23 p i assume p= plus?

That # is a 23pitch Mirage + . P is for pitch.

Took the boat out to put more hours on the rebuild and sort the freshwater cooling out. I was in and out of the throttle to help the rings seat and give the swap a general shakedown. 4000 rpm was 50mph on the GPS, it sure seems to burn gas but if I dont rid the world of dead dinosaurs who will?

I have a 95 272. when it had the factory 502, with CMI headers and an ECM re flash, it was a 62mph boat on gps, with 2 people and a half tank of fuel, running a bravo1 24p.
The second engine was a 540, with huge ported heads, HUGE cam, and every hp trick I know. The MPI was replaced with a more tuner friendly Carb set up and an MSD/Daytona Sensors ignition. Running a labbed bravo 1 26p, it would easily hit the the 5600rpm rev limiter and push it to low 80's. It was fun while it lasted. It is now running a 468 w ported Edelbrock heads a 235 degree cam and back to the 24p prop. I have not tried to see what top speed is, it planes easy and effortlessly runs at 65mph well below 5000rpm. Happy for now, too gunshy to chase mph. May take another run at a fast boat, but it will have twins and a better hull.