I made a little progress on the ZZZ-28 this weekend! 
I started setting up the Headers and a way of mounting them. 
First I cut eight 1" lengths of plastic tubing and cleaned them up. Then I set each set of the 4 pipes up 1/8" back on each one. Next glue was applied. 
 
  
  
I measured and figured where the Headers should exit the body and I cut a slot on each side.  
  
  
  
  
 I cut away part of the Belly pan to make room for the Headers. 
Then I fit a piece of sheet plastic to fit between the body sides, along the slot for the Headers. 
  
  
  
  
  
Here are the Headers in position. Looks like a good fit! 
  
  
  
  
  
Here is a photo of the Headers exiting the body.