Upon some good advice (thanks Sweet82!) I'm reposting my A/C question under a new title.

So here's the situation: My A/C evaporator core is gone but the rest of the entire system is intact and whoever removed it blocked the lines with plastic so no debris could get in. My question is will the system still be good? Like the seals and stuff? I'm thinking about getting a new core but only if I can be pretty sure the compressor and stuff still work, can I test it without the lines hooded up? I have no idea how long it's been that way but it's been at least a year and probably more.

all you need to do is change the compressor oil (it absorbs moisture) and the dryer. use the oil for the 134a since your changing it anyway.

make sure to take it to a shop and have them remove the air in the system, it will never perform to your expectations if you just put in the refrigerant without taking out the air in the lines.

my expansion valve always froze up after my system sat open that long. Might as well replace that and take all the other good advice offered.