Ok so here's a little history. 350 crate engine in the car from the PO - I don't have lots of info on the specs. Anyhoo, over the winter i swapped the holley for an edelbrock 650. When driving last week, the engine was jumpy when held around 3 grand. I checked the plugs and they were all burned and nasty. I replaced them with delco platinum. Gapped to .040. I inspected the wires and there was no damage.

I started the car and it runs great.. BUT now there's a popping sound coming from the exhaust about every 5-10 seconds. The pop is only there at idle.

So far i've changed the wires and adjusted the carb. I could not find a cracked plug.

Super confused here.. What could it be?

 

Still having issues. Anybody?