The one thing about a "kit" is that they are made to just add
freon....not to fill up the freon from dead empty.  IF you don't pull
a vaccum on the A/C system then you are wasting your time, when you
have replaced a major component or have swapped things out like the
original poster described.  

I also would suggest not to screw with those "A/C Refill Kits" anyway,
because you really need to know what you are doing before you even
think about screwing with the A/C system.

Most people don't have the appropriate type vaccum pump you need to
service an A/C system. Its not just simply run down to the store and
buy a can of freon and the little hose adapter and you are in
business.  You can get hurt if you don't know what you are doing.

Save yourself some headaches and consider the safety factor and just
carry the car to someone that has the proper tools and equipment to
service the A/C system.  I'm telling you there is an element of danger
with this....not to play around , but to make sure you understand
that.  Its kind of like messing around with home wiring...you think
its really easy until you get the crap shocked out of you then you
tend
to either do some better research and learn more or you just pay
someone else to do it for you.  Its one thing to get shocked by 120 v
its another to get hit with 220v.  

There are procedures to follow when charging the A/C system and there
are distinct fittings and a high and low pressure side. Yes freon is
expensive but if you get it done right....its a one time deal.

The other facet of having a Vaccum pulled is not only does it get rid
of moisture in the system you also can tell if you have any leaks in
the system prior to charging it with the expensive freon that can go
up in smoke.

Not trying to scare anyone but its far better to play it safe.
-----------
Elbert
ask@me.com