original a-body hemi headers on ebay

These headers and the Hooker ones I've seen did not have plates to bolt up to the reducers. If the original cars were required to have exhaust (per other posts), did all of the racers modify their headers?

Just saw your question, and figured I show you this picture.
Exhaust pipes were the slip on type as you say, and was like hooked to the torque shafts at the back side of the trans cross member. So exhaust pipes was required, but apparently not needed to be hooked up.
Other racer may have done this different, but the few pictures I have seen from ยด68-69, this is how it was done.
This rule was gone, or maybe kind of faded away, for the 1970 season and on, or maybe even earlier depending on witch organisation sanctioned the race.

And as usual, the now how guys are strongly recommended to step in and correct any missinformation on this Forum.

Picture deleted due to All Rights Reserved

20170407_125430 exhaust hook up.jpg