I picked up a set of NOS Doug Thorley headers recently that are orange.

Same color mine were, same decals too.

Do you know what application they fit?

As I recall, part numbers were stamped on the outer side of the flange that were visible when bolted to the head.

I do not. They look like they might fit a Chevelle, but the #8 pipe will hang below the frame right behind the front wheel if that's what it fits. I haven't test fit them in my Chevelle yet.

If they don't fit that, I'm thinking C2/C3 Corvette is most likely.

There were no stamps or anything anywhere. There's an ink stamp that looks like an inspector's mark, but no numbers that coincide with a part number.

I got a chance to try a test-fit on my '68 SS396, and they definitely do NOT fit a Chevelle.
#4 pipe interferes with the crossmember, so they can't go forward enough to line up with the heads. It's about an inch off, so not within hammering in some tolerance.

I think Doug Thorley (Doug's) headers from the late '60s and very early '70s were kind of a salmon orange color as seen in these vintage NOS hemi and AMC headers. It's not the same kind of orange like Chevy orange block paint.

A little off topic, but I have always been unclear if all three of these entities are the same "Doug"

Headers by Doug
Doug's Headers
Doug Thorley Headers

Anyone know for certain?

Yes, they are all the same entity.

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