Gen IV header to block interference help please
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Gen IV header to block interference help please 
Hello. I have a 2009 6.0 liter going into my Chevelle and I am attempting to install Speed Engineering headers. They are hitting the block in an area that I assume is a machining register. Does anyone know if I can grind into this area without fear of hitting water? I can foresee grinding about 3/4 of this tab off on either side of the rear of the block. Any thoughts are appreciated!
Better Pic.
Last edited by Chefordiac; Jun 20, 2017 at 07:48 AM.
How much interference is there? Did you have the gasket installed when mocking up? Seems like a pretty bad header design if it hits the block. I would find a work around before grinding on the block...
Andrew
Andrew
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There is still interference even with the gaskets in place. I spoke with Speed Engineering and they stated that they tuck the headers in tight in order to clear older narrow chassis. They also confirmed that this location is a machining register for the factory to use and grinding it down for this swap is fairly common. I'm going to dive in and if it works out I will post pics of the block. If I hit water the pics may be a lot different.....
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There's no reason to have to design LS headers in that fashion for any 64-72 A-body. The Hooker 1-7/8" mid-length and long-tube headers require no such clearancing of the block when used with the Hooker mounting components and clear everything in the car. Such issues are usually indicative of headers that were designed to hit a price point and not any particular fitment objective.
