A stock 525efi is a damn good motor, well underated at 525hp. And with simple maint. pretty damn dependable. Raceboats have been flogging the hell out of them for years... Why mess with a good thing?? Merc put a lot of thought and dollars into making it a solid package.

525 EFI
Crane Hyd Roller
298º/306º @ .004"
236º/244º @.050"
.610"/.632" Valve Lift
114º LSA

Comp XM284HR
230,236 at .050"
.547"/.547" valve lift
112LSA

Merc 500EFI cam:
Crane HR
230/236 at .050"
.598"/.610" valve lift
114LSA

But the guy down at Autozone said big valves with a little cam is one of those secrets that nobody knows about........

He works for Autozone now ? Weird, as you have to know how to install batteries if you work there right ?

Well he does have a 50/50 chance of getting it right...

What's done is done. Let's focus on how to fix it. Is there any point to get a cam with more duration and lift than the stock cam or am I just better off switching to a stock 525efi cam?

money,lots of money
as for a cam,,crane 741 or what ever number they list it as now.

So nothing to gain by using something other than stock cam? Maybe that's just the best cam overall as I'm not using the boat for racing exept for a pokerrun once a year.

As stated above the 525 EFI is one well thought out and very reliable package. I have two, 12 years without a single hiccup. Just went thru them and found not a single thing that indicated a need to rethink what Merc racing built. We did up grade the valve springs and used Crower SS rockers in place of the Crane. All else was not dicked with, case of "If it ain't broke, don't fix it".

A plan here might be to work toward getting the motor back to where Merc had it. I think that would satisfy your goal. Then if you feel you want more RPM you can use the Whipple reprogram and reset the limiter to 6000 along with a few other little tweeks.

You're probably right. I'm going to drive it as it is this Summer but probably best to go through the engine in the Winter to see what's what and then continue from there.