I have a '95 351 which I am in the process of swapping in place of my 300 six; The 351 is stock but the y-pipe I've got has an A/F sensor at the junction in between the two pipes right before they join into the rear flange. I had planned to hook up the air injection tube but there is no where to hook it up to on the y-pipe...

Frank

 

It is supposed to connect to the cat converter.

 

Thanks Paul!! The air tube connection on my old 300 six was at the y-pipe....that's why I was confused...

 

What did this motor come out of? A 1/2 ton or something heavier? Does you Y-pipe look like this? If so the bung to the right is where the air tube would connect.