It's supposedly same cam 900-1075 so maybe different springs, valve seats etc used on 900's that take a pounding. Not sure. Regardless you'd think Merc Racing would have endless R&D hours and could have come up with something with less maintenance/replacement intervals. I thought they used same or similar to your Teague SC's in the 1075's but evidently not. At least from what I could find out here on OSO. I've got two on the shelf but have my eyes on a couple with less aggressive lobes. Mike keep your old cam. I'd like to mock up and compare sometime.

Our boat had 588 ci super charger engines in it when we got it. For us we just wanted something a little different then the norm.

Plus the sound of 600 ci NA engines with 4 1/2 tail pipes has got to sound mean lol.

The real big plus for us is that our insurance will come down alot.

I agree that you should make “more steam with more head”. Also most like a small bore....

Why do you say most people like small bore engines?

Just having a cup of coffee playing with the Pipemax program.

606ci turning 6500RPM, making 900HP.

Recommended valve lift = MIN .786 Normal .885 Max 975
Required intake flow 381-404 CFM at .874 valve lift
Required exhaust flow 275-298 CFM at .948 valve lift
Carb CFM 1175-1440
Recommended cylinder head Cross sectional area 3.523 (A 357cc AFR has 3.435 min csa for reference)

Headers for low to midrange power
2.10 to 2.225 " Primary ID 32.4 to 35.6 inches long

Midrange to upper rpm power
2.30 to 2.425" Primary ID 32.4 to 35.6 inches long

Collector diameter
4.051 to 4.301 best for tq
4.301 to 4.801 best for HP

Not sure a set of Gils or E Tops would work well on this monster, or a "741" cam :)

Dropping to a 2.25 valve from the 2.40 , minimum lift requirement increases from .786 to .838 .

Dropping the max RPM from 6500, down to 6000, minimum lift requirement decreases from .786 to .725 with the 2.40 valve.

MILD THUNDER What bore and stroke are you using in that combo?

Would be nice see it for your 600 ci combo.