VOV same as restrictor?

[Perry, Christoper (EDS)]

Hey I am going to do a r-134 conversion on my 89 90q and I have heard talk
of a Variable Orifice Valve (VOV) lately. I see that my car has something
called a restrictor and I was wondering if that is the same thing as a VOV
and should I replace it when I do the conversion.  I know that I have a
Nippondenso compressor and I am planning to replace the receiver/drier (or
accumulator) while the system is empty.

TIA,
Chris Perry