I put one in my 525SC (pictured above) but only did the top end and never dyno'd it. I gained about 150-200 rpms over the stock flat tappet and would touch the 5400rpm rev limiter with light fuel.
The 731 is nearly identical to a 500EFI cam, so I'd guess peak hp around 5300-5400.

Thanks Griff... With my pair of baby 482cid sized engines both making exactly 510hp each on the dyno at only 5000rpm, then I can only conclude that it's probably because of the Merc Thunderbolt distributors and the Rev Limiter chip it has in it. 🧐

Similar ?
 

don’t know how much similarity there is to the 500 to 525 cams but I have been happy with performance on mine all the way around

What Thunderbolts??? TB IV's don't have rev limiters, but TB V's do and are built into the module.
You would know if its hitting a rev limiter. RPM's would bounce 200 rpms or so back and forth at WOT.

The Hp500 cam is the ‘721 cam. Merc never used the 731. The 500efi cam is not same as 731.
i have listings here, old speedwake, bf’s, and others ??? With all the crane marine hr’s cams. If one can’t find i’ try.

Heres is 1 of’m

​​​​​​​

Thanks Griff, I am NOT exactly sure which of the Merc Thunderbolt distributor setups that are on my 482's, but they have that flat looking module with ID numbers on it and I will definitely take a look at it when I get my boat out of Winter storage.
My 482's were built and dyno tested back in 2008 and have not been run since that time until last Fall. I will have to try to find the dyno sheets but I specifically remember them both being Dyno'd @ EXACTLY 5000rpm each... but I don't recall how the RPM's reacted etc after 5000rpm on the dyno sheets.