which headers are best?

All depends on what "best" means. A set of $189 Hedman 78030 B-body headers will fit a low-deck big block, manual steering, mini-starter A-body with just a few small dimples... BBD has the pics, and I put them on my car too.
B-Body Headers In An A-Body

Certainly the $800 TTI's will breathe better at the top end. "Speed costs money, son. How fast do you want to go"? ;)

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uh... "Never Mind", didn't realize the question was about a small block. Sorry.