i got a pair of flow tech headers, i got the drivers side in pretty easily, but the pass side is difficult, the headers hits a part of the tranny the flange for the dust cover and the frame that sticks out abit.. i have a automatic if you need to know,

 

is it interfereing with just the installation (ie...sliding into place) or is it in the way of the header being bolted in place?

if it's the first, remove the motor mount bolt and jack the motor up a couple inches.

if its the second...i say they are the wrong headers. got a sawzall

 

yep... number 2... sawzall...