<VV> Fw: Exhaust port tube fit to manifold

[Doug Mackintosh]

Andy Kinzelman pointed out that I did not ask the question I meant to ask in my original post. My Title was correct, but I bungled my question. 
The issue I am dealing with is a loose fit between the exhaust port tube and the MANIFOLD,  not the head.
 
Sorry for the confusion, and if you answered the question I asked, please feel free to answer the question I MEANT to ask now.
 

-- Doug Mackintosh
Corsa member since 1996
Corsa/NC member since 1996,  Virtual Vairs member
Corvair owner 1969-1971 and 1996-on
 
----- Forwarded Message -----
From: Doug Mackintosh <dougmackintosh at yahoo.com>
To: Virtual Vairs <virtualvairs at corvair.org> 
Sent: Monday, 17 September 2012, 12:12
Subject: Exhaust port tube fit to manifold
  

I have to replace some the exhaust port tubes in the heads of the engine I am working on, because the donut seats are torn. I have some used tubes.  
According to the 1961 shop manual the tube ends are a press fit into the exhaust manifold (as well as into the head). The used tubes I have are a sloppy fit in the head (missing a press fit by as much as 0.031 inch).  
  
Any experience on the list with this. Should I use these, or do I have to bite the bullet and purchase more used ones? I am guessing the press fit would help with heat transfer from the tube to the exhaust manifold, but as a practical matter, does anyone know what will actually happen if the fit is sloppy? 
  
Thanks!  

-- Doug Mackintosh
Corsa member since 1996
Corsa/NC member since 1996, Virtual Vairs member
Corvair owner 1969-1971 and 1996-on