I have had to cut apart that tube and reweld it, but lately the headers I have been getting have fit nicely. Do you have the engine installed in the chassis level? Have you cut the tacks on the tube and tried to move it around on the flange?
Shelby does have a set of headers for an aluminum car that route that tube under the steering shaft. Maybe you can replace that one tube?
Shelby headers can be a nightmare.
