Replacement headers for 525 EFI - Which ones?
 

I'm going to replace the headers on my 525 EFI's. I've read most of the threads on here about the various products, but many of these threads / comments are several years old so I'd be interested to know if experiences have changed since then and what the collective wisdom is now on what headers are holding up best. I have a 2005 38' Fountain with semi-staggered engines and silent choice exhaust; the engines are 2004 models.

I know you may be a little sore to CMI, but I wouldn't look away from them. All headers will eventually leak, however they followed the merc spec to meet a price point and went cheap on the metallurgy for the stock 525 header. They have an upgraded version that will last, and match right up to your existing tails.

I would at least call them. Maybe they will work something out for you, or at least prep your old headers for resale.

I've owned this boat for a total of 6 weeks, so I'm obviously not too happy about this, but I'm not sore to CMI because of it. But knowing there's a problem with them and now having to spend a decent amount of dough to rebuild my top end because of it, I just want to replace them to avoid a catastrophic failure. At this point, I'm going to spend the money, so I'd just like to get the best option available and wouldn't rule anything out. Is the upgraded version you're referring to the Gen-X header?

Stainless marine 525 replacement headers. Will outperform the CMI and have a 5 year warranty (nobody in the industry even comes close). May not look as good but you will eliminate the one flaw 525's have by putting the stainless marine exhaust on. A lot of the race boats run the stainless marine because they care about performance and reliability, not looks...

http://www.stainlessmarine.com/?wpsc...=01-1260010-00

hardin marine 525 lites,,,direct replacement

I agree SM is a safer options, however aside from bling you also lose that raspy header sound.

The stainless marines are now a direct replacement and the stainless marine definitely sounds the same as a header, if not louder. If he wants the noise then he can go completely dry. Everybody who bashes the stainless marines have never had them or dealt with them. Look at some old threads on here and see what people have to say about them. Like the old saying goes, what people don't know, they don't like.

The issue with the SM headers is having to re-tap the block to fit their bolting pattern; not a huge deal, I guess, but adds to the overall cost of this project. Would have to believe there is an alternative that I can just bolt on.

They now have a direct replacement??? Their website says this:


Note: The exhaust bolt patterns on the heads are not the same as the standard GM. Precision drill & tap gigs are provided to match the original GM exhaust head bolt patterns. For more information, please consult with our application sales representative.

I have had SM on tow of my boats. One had dry tails. The exhaust was wonderful IMO, however I can still tell the difference of a boat with headers vs one with manifolds by the exhaust note, not the volume. Again, headers add bling, spark plug access, better access between engines, and a different note. SM exhaust adds security in a fresh water environment. Salt water will erode the cast aluminum lowers faster than they effect true stainless headers.

On another note, one of my old engines got hot and the gauge did not show until it was too late. The sensor was relocated with the addition of blowers and was too far from the engine to show an immediate heat issue. Had the engine rebuilt and shortly after the SM exhaust failed internally. The heat from the exhaust without water caused fatigue and the manifold let loose on my new engine and destroyed that with water. So.....none of them are safe :D