I haven't pulled my manifolds so I have a question about the spacing. Are the heads symetrical as far as the header bolts? My engine is a 1994 4.9 from a Seville. I was wondering if the exhaust manifolds can be swapped and turned upside down to face upwards instead of down? This is for my turbo 4.9 swap and would be used in place of the 4.9 Deville setup with one outlet welded closed. Of course I'll get the answer to this myself once I get both manifolds off, but I'm curious if anyone has the answer to this "trivia" question. If this can be done what combination of manifolds would work for it?

[This message has been edited by vafierro (edited 02-26-2007).]

You can swap sides - but you can't turn them upside down (have a look at the bolt pattern ans you will see why). If you need to to face upwards - try using the Deville manifolds.