What kind of Headers are these? (Just added pics)

Hay Myasylum did you ever use these to try them out? Or perhaps someone else has these and tried em?

I picked up a set for $40 last winter, I was told by the seller that they were for a small block a-body application. I could see they were for small block and I figured for the price I'd pick em up and try em eventually. They have the same numbering stamped into the flanges as yours. I could not find any other markings on em anywhere.

I'll be mocking them up by next weekend on a 360 bare block and heads with a 727 to see if they clear the trans but wont be able to know if they will clear power steering until I do a swap... which unfortunately may not be until very late next year or the year after unless I win a lotto! lol

510 Headers.jpg