When I floor my car it seems like it's missing and it's loosing power at higher RPMs. I just got done putting longtube headers on, I have fairly new plugs, wires, and distributer. I don't know whats up with it I'm just wondering if anyone could help out.

 

It's common for people to melt the insulators on the spark plugs wires with long tubes. Make sure your wires haven't been damaged allowing the spark to short to the headers/block.