I didn't know anyone else made a header for the Edelbrock alum head, and how about Merc. changing the bolt pattern so everyone with 525,600,700 would have to buy them from them

Mind Sharing how you pickle them? I'm interested.

What about Hardin Marine Hurricane?

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

Do not buy the Merc headers; you will pay almost double and not get any better quality than the Gen-X headers. I bought a set of Gen-X headers last year and they were a direct replacement. I only had that boat through the end of the season so can't really comment on longevity of them but they are supposedly better than the original Merc spec CMI's. I have seen one person comment on here about a set of Gen-X's developing leaks pretty early so buyer beware. When I was at the Miami boat show this past February, I got a look at the Hardin Marine Hurricane Lites for 525's and they looked great and seemed very solid but noone seems to know much about them. If I were replacing my headers now, it would be a toss up between the Gen-X's and the Hardins. No matter which you get, the reality is you to need to take care of them. 1) Do your best not to let them overheat. 2) drain them after they cool.. 3) pressure test at regular intervals..

I pressure test every 10-15 hours with this...

[ATTACH=CONFIG]528237[/ATTACH]

The tester consists of a pressure regulator, 1/4" ball valve and pressure gauge and a bunch of fittings to get it all together. First, I block off the water inlet and outlet with 1" rubber furniture stoppers and hose clamps. I hook one end of the tester to an air compressor and the other end to the 3/4" fitting on the header. Then I open the small blue drain plug and let some air in to purge any remaining water in the headers so they're empty for the test. Next, I set the regulator to 60 psi, open the valve to fill the header with air, close the valve, then monitor the gauge to see if there is any loss in pressure. It really works great and will tell you if you have any leaks before they really bite you. It's easy, safe and you can do it pretty regularly without taking the headers off. It's basically a leakdown test for your headers..

That page says:
So...you have to drill and tap your Merc/Eddy heads ?

2 gallons of antifreeze with 3 gallons of water in a 5 gallon pickle bucket. Run motors till hot, switch hose to draw out of pickle bucket, pull through until the buckets almost empty and shut down. I drain off whats sitting in the headers and the blocks and the heat makes a nice vapor that coats everything. Works great. I do this if the boats going to sit more than a few weeks and for sure when laying up over the winter.

Salt water left behind in a hot motor is probably the single worse thing you can do to your headers other than overheating them.

Apparently, I knew that was the case before but saw the advertisement last week as "525 replacements" and assumed they changed the bolt pattern. Apparently all they changed was the marketing.

yes,4 holes have to be drilled and tapped,,search here,gaskets have been compared.

Gotta side with Tank on this one. Their name is on the headers, it's their product, otherwise it should have been built for Merc with the Merc name on the pipes if CMI had issues with the design. That design cost many people big bucks to fix, time out of the boat, and a large measure of hassle. It's not like it's a broken $50 part, this is serious stuff. And regarding their squabbles with Merc, they shouldn't have to drag the customer into their design issues with their client, that should have been settled between the two parties and the problems worked out before shipping a questionable product.