>Has anyone, or does anyone know if the early, federal, late '70's muffler
>will fit '80 heater boxes? I acknowledge that removing the catalyst from 
>the system is not exactly legal; but I know for a fact that a properly 
>maintained engine without a catalyst is much more efficient and cleaner 
>burning that a poorly maintained, cat-equipped engine!

Yes, a '72-74 Bus exhaust will fit an air-cooled Vanagon (and also will fit 
a '79 bus), other than the lack of the CAT.  
I have a complete aftermarket system (muffler and pipes) for $79 for the 
whole thing, and have sold several to Vanagon owners.  This seems to be the 
most popular option; it isn't as heavy duty as the German '72-74 exhaust, 
but for a fraction of  the price it does a fine job.

-Ron Salmon
 The Bus Depot 
 http://www.busdepot.com