[scratch]

Jack,
Try finding a tailpipe expander and enlarge the last couple of inches to the header tubes. A muffler shop can do the same, it takes a bit of power to expand some tubes (because of wall thickness).

You may want to try 1, or 2 tubes at first and this may do the trick. If you do all of them, it's a ***** to fit them into to sidepipe.

Go slow and find the right fit.

Scratch...