Mating 525 headers to a 496....????
 

Can it be done by just re-drilling the bolt pattern? I know those headers will work on a 500/502 and vica versa, non-525 headers will work on 525's with bolt patterns altered, but someone is asking if these things will work on a 496.

Yes, you can redrill them to fit a 496, but its the rest of the raw water plumbing and accessories like oil filter, ECM and harness brackets that will test your fabrication skills and patienance!

Regards,
Ray @ Raylar

Why would you want to. The 525 headers are the worst.

[QUOTE=fountain40icbm;2341935]Why would you want to. The 525 headers are the worst.[/QUOTE
Really? I guess Mercury High perf must not know what they are doing. You should contact Merc, and tell them what you use, or maybe you build a better header yourself? If you do, PLEASE, let use all know. Maybe Merc can save money on R&D with your advice, use your header, and save everyone that runs Merc High perf motors.
Bawana

[QUOTE=Bawana;2343251]You mean CMI not Merc?? They're CMI headers buddy specifically designed only for the Merc 525's. Do you have a relationship with Merc or something. Everyone knows they're stuff is junk but they own the market. Have you even owned any and actually used the boat. We have repaired ours multiple times, and many, many others. Just because may you own them doesnt make them good. There have been countless accounts on here about people loosing motors due to header failures on the 525's.

[QUOTE=Bawana;2343251]You've got 36 posts, and you're already jumping down poeple's throats??? Where is it written than everything Mercury Marine builds is perfect?

Michael

TIME OUT EVERYBODY!!!!

The reason I asked is that I have a spare GOOD set I want to sell. Someone inquired about their matability to a 496. That's all I wanted to check. I already emailed the guy back letting him know that these were not right for him and he should check out the aftermarket ones made for the 496.

We all know that the CMI's had issues and neither them nor Merc want to accept any responsibility for some cooked motors. Thankfully I haven't had too much trouble with mine as I flush with salt-away and drain them every time.

Just remember if you have diverters, never use them above 1500 RPM!

Thanks Ray, for the Tech Info.

[QUOTE=fountain40icbm;2343293]Mercury specified and only CMI built. They are a different alloy and specification than standard CMI product.

Don't fault CMI for this issue. We can't even buy them as a distributor. Merc only.

[QUOTE=Michael1;2343347]I am sorry if I offended someone here. I do take issue with the fact that someone asked a question, Raylar answered, and someone had to bash! Oh ya, I only have 36 posts, BUT, I have over 30 years in marine High perf. There is a reason that great men such as Moore, Tomlinson,Teague,Zelinski,Riggs, DeAnabele,etc. do not chime in one this site any more. OSO is a great site, I live for offshore boating, I respect anyone on the water, yes even sail boaters and fishermen. If I can help anyone with a problem, I am more willing to help; If I don't know the answer, I know enough people in the industry that I can send you to. I don't hide behind a computer, you can call me 920-475-0852
Bawana

Repairing 525EFI after first header failure $20,000.00
Repairing 525EFI again 4 hours later after second failure $20,000.00
Merc and CMI executives laughing at us while playing golf... priceless