I've seen one later model full stagger. I've also seen a full stagger 42 with 496s. 1 of each ever. Lol. I know what you mean beck see 38 fevers came with 502 mags forever.

There is no reason to fear the 525. They are awesome motors. Easy to work on, easy to get parts for and generally very reliable. Mine start every time I turn the key. If you take care of them, them will take care of you.

Header,s & long heavy tails need support or tie bar,s , someone need,s to put a gopro in the engine compartment & watch that stuff move and shake .

Springs and rockers are not a real big deal or expense, especially if it avoids a catastrophe! Some folks have suggested a full valve job though.... What's your take on that?

The other week I spoke to a reputable engine builder on the West Coast of Florida. I was ready to drag my boat to Florida to have valve springs, etc. done. He told me to save my money and wait until rebuild time at the 450ish hour time frame. He said installing new springs / valve job is a waste of money as it will be replaced when you rebuild and you run the change of pushing oil. His recommendation was change oil every 20 - 25 hours, new plugs every year, pressure test or replace the headers.

Everyone has an opinion I assume and if it is mechanical there is the chance something could always fail.

I have a 2005 35 Lightning with 525's and 466 hours on them. Never been touched. Getting ready to do the top ends and pressure test the headers. and maybe the ECU's while I'm in there DO NOT be scared of the 525's with 250+ hours.

I did leak down test at 400 hours. Inspected each cylinder with remote camera. All was good. I replaced the springs, keepers and retainers. Stayed with stock spec springs. Original '07 vintage headers still fine. Fresh water boat. Single engine so no long pipes.

I am just over 300 on mine. Oil changes every 25 +/- hours, used but not abused, they still run as strong or stronger than when I first bought the boat. I have wrangled with this freshen up question for some time now. Feel like the top ends would be a reasonable direction to go in but have had some tell me " if it ain't broke! " This boat had 40 hours on it when I bought it almost nine years ago and it has never given me so much as a hiccup in all these years. Respectable care is one thing but tearing into a pair of perfectly good running engines just for chits and giggles is just plain stupid, in my book.


Side note here. I did have a pair of carb 500's that took the valve spring dump at 187 hours. So I am not living in lala land.
But 525's are not 500's, not even close.

I had a rocker explode at 200 hours sending needle bearings everywhere. Cost me a new long block. Guys that work on dozens of 525's have seen a trend in spring / rocker failures around the 200 - 250 hour mark leading them to believe there is a systemic issue with OEM components. Some even less than that. There are also plenty of 525's that run for 100's more hours without a single problem. Had I not had that failure, I probably wouldn't have touched mine until I got to 300+, but I did and decided to redo the top end preventatively. Cost me the money for the parts, but I did the work myself. IMO, was worth it.

I don't think a full valve job is warranted unless there is a reason. ie: do a leakdown test and see what your results are. When you change the springs, you should also change the valve seals so you can inspect the guides (from the top at least).