On my 340 Cuda, the driver's side is the nightmare.
Heat up the offending tube(s) to cherry red with your handy propane torch, grab a socket extension, ball ping hammer, or a punch and "dink" the tube so you can get your bolt in there. Keep in mind you don't have to pound on it like Hulk Hogan ... the heat and repetition do the work for you.
"But I don't want to dent my new headers!"
As much as you might think they'll be on there for the duration and you'll never ever have to go through all this bs again, you will. :-D If you're having trouble getting them installed now you'll have the same trouble later. If you do manage to hold your tongue just right and get that squirrely bolt in there somehow, imagine the fun you'll have trying to take it out. Fix it now while they're off the car.
