>Has anyone tried switching the vanagon rear heater
>core for a different model???

I test drove a van last Summer where the owner had substituted a metal
oil cooler for the stock heater.  He had to butcher the plastic enclosure
to get it in.  Can't comment on how well it worked producing heat.  I
think he removed the on/off valve also.

Tony

Anthony L. Mourkas
Hampden, Maine, USA
1984 Vanagon Westfalia
1987 Vanagon GL Syncro
1991 Jetta Eco Diesel