Dissapointing performance

I almost forgot start to learn on how to read a spark plug as well as indexing your plugs. the right ignition system helps a lot.
Thank you for your opinions. I understand plugs so well that I know black plugs work as good as any plug. When I first fired up my engine after rebuild with white beautiful plugs, the car worked same way as it does now with black plugs. Have you readed the link what I posted about spark plug basics?