So Angela & Will says:
> 
> We are looking for something that will show the differences of the V.W. 
> campers.  If anybody knows of anything (book, magazine, or likewise) 
> please let us know. We like the way the front hinged pop top looks (up 
> to '73?). Is there a major difference between the '73s and '74s? We are 
> looking forward to purchasing one.  Thank you for all comments.
> 

Bodywise, I don't believe there is much difference at all between the
'74 and '73's.  Mechanically though, if you are in California, it has
a somewhat different emission control setup.  The '73 has two EGR valves.
Each of which are attached directly to the manifold.  They are a major
pain (really impossible) to locate replacements for.  The '74 has a
single EGR valve that stands alone and is far easier and relatively
less expensive to replace.  They both have the dual carbs which can
be tough to balance at first, but once done, they are quite good.  Others
will dispute this, but I really had no problem with mine other than 
the initial balancing which I finally had the dealer do for me.  
In the second half of '74, they went to fuel injection and I know
little about this setup.

Camper wise, I believe they are identical.

Take the '74 over the '73 unless you're outside of California.
In the latter case, take the one with the least rust.

Steven 

sjohnson@pcocd2.intel.com