Looking at the pictures, I'd say you've got
6" to the header flange Yes
8-1/2" to the frame Between 8.5 and 9
2-3/4" from the frame to the LCA Roughly
26 5/8" to the fender lip Yes it was slightly less than 27
Sound about right? It can be hard to tell just from the pictures because the view angle changes things a bit. Now, the next question I have for you is, are the header flanges the lowest part of the header?
Yes.
If there's a tube that runs below the steering link, it's probably lower than the flange right?
No, well maybe, lol. I'd have to double check. I think it's pretty close to even.
Anyway, if my estimates from your pictures are right, it means that your headers flanges hang down 2-1/2" below your frame. The Doug's are at 2-1/16".
And to answer your question, yes, my car has been lowered. I run 1.12" torsion bars with a poly bumpstop on the LCA for additional clearance. Looking at your LCA measurement, my car is lowered about 1-3/8" from yours at the suspension. Obviously there are still ground clearance differences because it looks like my tires are a bit taller.