Impossible to install spark plugs!

So I’m thinking wow things are going so great on the reassembly of my car. Something has to go wrong this is too good. Then bam what I expected happens. So I’m about to put the new champion plugs in my 383 in which I just installed edelbrock rpm aluminum heads and finally got my tti headers back in. What a pain in the *** getting those in. Then I realize that you can’t install spark plugs in the aluminum heads with the the tti header flanges bolted to the engine. WTF? The bottom of the header flange plus the bump out on the bottom edge of the head combine to make it impossible to install the plugs. Sure they use a standard 13/16 inch socket and it fits over the plug but the material that is in the way only allows you to get the plug in a small amount. The flange and bottom raised edge of the aluminum head get in the way and prevent the plug from seating. Has anyone had experience with this? If so was the solution to take a carbide Metal cutting/sanding bit put it in my drill and carefully grind away the area on the head and at the bottom of the header flange to open up the area around the plug hole? Did this work for anyone? I’m so frustrated. I never heard of this issue before when installing tti headers on the aluminum heads in an a body. Please help!