I think that screwing with headers on a pontiac is just a rite of passage.
I had to replace a weeping head gasket and when bolting the headers back up I spent over an hour just getting one bolt started on the passenger side behind #6. And I know that some people have spent much, much more time than that.
My friend bought a nice set of coated hedmans for his 69 GTO and we had to fight them in. Scratched them up too

but they still looked nice. Now they are leaking

so we get to do it again.
I've got some 2 inch super comps coming and I can't wait to install them