Notices
General Boating Discussion

mercruiser 525 headers

Thread Tools
 
Old 01-08-2012 | 09:26 AM
  #1  
Thread Starter
Registered
 
Joined: Aug 2001
Posts: 214
Likes: 0
From: lake of the ozarks,missouri
Default mercruiser 525 headers

i should know this but i dont,will the factory cmi 525 headers bolt up to standard bbc heads??
proboat-wes is offline  
Reply
Old 01-08-2012 | 09:32 AM
  #2  
glassdave's Avatar
Neno the mind boggler
20 Year Member
Super Moderators
 
Joined: Sep 2001
Posts: 13,080
Likes: 320
From: toledo oh
Default

Yep
__________________
Throttles- Cleveland Construction 377 Talon
08 OPA Class 1 National Champion
08 Class 1 Geico Triple Crown Champion
08 OPA High Points Champion
10 OPA Class 1 National Champion ( happy now Ed! )
glassdave is offline  
Reply
Old 01-08-2012 | 09:32 AM
  #3  
Registered
 
Joined: Dec 2004
Posts: 3,194
Likes: 5
From: hampstead nh
Default

Originally Posted by proboat-wes
i should know this but i dont,will the factory cmi 525 headers bolt up to standard bbc heads??
no. but they can be modified .need to drill 4 holes on each header .the 525 s have a 3/8 ths offset bolt on each cyl . nice that merc did that so you could only use their headers

Last edited by smokin' gun; 01-08-2012 at 10:10 AM.
smokin' gun is offline  
Reply
Old 01-08-2012 | 09:43 AM
  #4  
glassdave's Avatar
Neno the mind boggler
20 Year Member
Super Moderators
 
Joined: Sep 2001
Posts: 13,080
Likes: 320
From: toledo oh
Default

Originally Posted by smokin' gun
no. but they can be modified .need to drill 4 holes on each header .the 525 s have a 3/8 ths offset bolt on each cyl . nice that merc did that so you could on use their headers
Oops . . . . Are the 500 and 525 different headers?
__________________
Throttles- Cleveland Construction 377 Talon
08 OPA Class 1 National Champion
08 Class 1 Geico Triple Crown Champion
08 OPA High Points Champion
10 OPA Class 1 National Champion ( happy now Ed! )
glassdave is offline  
Reply
Old 01-08-2012 | 09:52 AM
  #5  
Registered
 
Joined: Dec 2004
Posts: 3,194
Likes: 5
From: hampstead nh
Default

Originally Posted by glassdave
Oops . . . . Are the 500 and 525 different headers?
yes they are .525 600 and 700 .i think once the patent ran out cmi will make them w both patterns .i think they do now
smokin' gun is offline  
Reply
Old 01-08-2012 | 10:00 AM
  #6  
Registered
 
Joined: Oct 2005
Posts: 5,825
Likes: 612
From: Clarkston, Michigan
Default

Bolt pattern is different on the 525 heads but they can probably be redrilled as mentioned. There is not much room for the end hole though.
thirdchildhood is offline  
Reply
Old 01-08-2012 | 10:02 AM
  #7  
Thread Starter
Registered
 
Joined: Aug 2001
Posts: 214
Likes: 0
From: lake of the ozarks,missouri
Default

thanks for the help. when the headers show up this week ill fire the drill up and reposition the holes according to my exhaust gaskets,wes
proboat-wes is offline  
Reply
Old 01-08-2012 | 10:12 AM
  #8  
Registered
 
Joined: Dec 2004
Posts: 3,194
Likes: 5
From: hampstead nh
Default

easy to do just copy the gasket . but the stainless flange is tough to drill
smokin' gun is offline  
Reply
Old 01-08-2012 | 10:23 AM
  #9  
tcwcar's Avatar
Joe
 
Joined: Aug 2010
Posts: 702
Likes: 2
From: SE Pennsylvania
Default

so does hold true for set of 99 etop 500 efi headers too, just bought a set of AfR heads, didn't bother to check to see if the header bolt up...
tcwcar is offline  
Reply
Old 01-08-2012 | 10:48 AM
  #10  
Registered
 
Joined: Dec 2004
Posts: 3,194
Likes: 5
From: hampstead nh
Default

no only . only 525s 600 700
smokin' gun is offline  
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.