Whether you need to modify them to flip them depends on the header, they don't need to be headers for a 60's Mustang or even for a Mustang....you could find tight fitting block hugger type headers for a SBF in a hot rod and make them work. Besides, if you're talking about putting a turbo in a 60's Mustang you're going to be modifying stuff anyway. Having to tweak existing headers to make them fit is less work than fabricating headers up sometimes(depending on how much tweaking is needed). I can see where it would be an issue with a 351W and it's 9.5" deck height, but with block hugging headers it wouldn't take much to make it fit. Changing plugs might be a complete pia though.

Personally, if I were building a turbo 408 it'd be off a Dart block and the entire exhaust would be custom, including the manifolds. You're going to be so much money into a project like that(to make it hold together) that the extra money on custom fabbed manifolds is a drop in the bucket.

And by a ton of boost I'm speaking of boost pressure on pump fuel. A blow through carb with an intercooler on 8-8.5:1 compression ran easily run 15-20psi on pump fuel, and more depending on the setup.

And the general rule of thumb is a stock 351w block will take around 600-650 at the crank properly tuned. But that gets back to my original point....a turbo 408 is an absolute beast, and you're not going to be running stock anything unless you like driving a bomb.

 

Who was it that put a bump in the floor under the rear seat area for the turbos to be rear mounted? They used half of a LP bottle for the floor board hump.

 

67 evil eleanor.... How can you forget .

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