Header size and Brand

I have a 540 stroker(440) in a 68 dart, the headers installed now have very little clearance on #5 and 6 cycl to install a plug and wire end. The header tube on these exit through the fender well. I want to use ceramic ends to protect the plug wire but don't have the room. They are 2" headers, is this the correct size for the engine? Is there a brand header that has more clearance for the plugs and wire ends?