Need help with exhaust parts

[Clutch]

I have a 1977, 2.7. I have rebuilt the engine and am in the process of replacing some of the unserviceable exhaust parts. It seems the parts pictures (Pelican, Stoddard etc.) does not match what I have (I have a non-California set up). My crossover pipe gets wider about four inches before the end, the end going towards the catalytic converter. This larger diameter is designed to accommodate the pipe that attaches to the catalytic converter. The piece of pipe attached to the (cat) slides into the crossover pipe, then can be clamped into place. Does any body know what I am talking about? Where can I get the piece that attaches to the (cat) and slides into the crossover pipe?

[john walker's workshop]

i might have one upstairs in the parts stash. or you could replace the whole length with the later unit with the bellows. might have that too. used of course.