SCAT Tube Sizes for the Engine Bay - 1984 M20J

[MisfitSELF]

1984 M20J.  Lycoming IO-360-A3B6.

My SCAT tubing is due for replacement (I'm at the point I'm putting RTV on top of RTV to fill the holes).  Unfortunately the Mooney Part book calls out a special Mooney part (640001-027) and I can't figure out the equivalent SCAT size.  I'm specifically looking for the diameter of the tube that goes from the muffler shroud to the cabin heat. 

I think it's 2.5 inches (or a -10?) but the previous tube (thats 2.5 inches) looks like it was flared out to fit on the attachments.  So is a 2 3/4 inches (-11?) a better fit?

While we are at it I'd love to get the dimensions of the other tubes if someone knows.  I've been "practicing" with the tube I've removed to see if I can cut it and fit it probably but I can't quite get it over the  attachments on either side as easily as those youtube videos make it look. 

Sorry for the story and thanks,

Bruce

[jetdriven]

the rear piece is 2.5" x 36, the front is 2",  not as sure the length, 24" IIRC is a couple inches short.