The engine is supposed to be 2" offset to the passenger's side. My TTIs did not fit either until I shimmed the motor mounts to get the engine in the correct location. The factory k-frames are really sloppy and the tolerances are wide. Some k-frames are better then others. I have always had problems with headers in my car and the reason is the k-frame. Once I got the engine sitting in there according to TTI specs the headers cleared everything. No dents were needed.
You can down load the TTI instructions which have the engine location specifications from here:
http://www.ttiexhaust.com/Header-Small Block/340ABE.htm
