No power

[Nick lenz]

The owner I bought from said rebiult. I believe him from how clean it is had valve covers off and was as clean as can be under those and paint still on engine. I will do a compression test on it.

 

[Blackwater]

Its your O2 sensor. When you swapped to headers it removes some of the heat to the O2 sensor causing it to not mix the fuel air correctly. swap it with a heated O2 sensor you can get from TBI chips or summit.