I copied this from a post Danny made. John left this reply. I am pretty sure i had seen them with the capacitor but i didnt find it in the AIM. Thanks!
coil bracket with the "notch" is not unique to the Z/28; originals don't have the notch, although the eBay sellers want you to believe they did, so they can claim they're "rare". The one in the photo is clearly from another application, as it has the screw to attach the radio noise suppresson capacitor, which was never used on a '69 Camaro.