1990 ford mustang ac help

I am so frustrated. I have a 1990 mustang with factory air.Last year, I attempted to retrofit the car. However, the receiver drier I purchased would not attach to the compressor manifold/blocks. Inside the low pressure block was some sort of clip or something that kept the hose that is part of the receiver/dryer from going all the way in. I tried to pry it out and basically ruined the block. This year I attempted to do this again and paid 80 bucks for a used compressor off of ebay just to get the blocks because I could not fin them anywhere. And those have this clip or whatever it is too.

I thought maybe autozone gave me the wrong receiver/dryer so I had them order another one and it is exactly like the old one. All I want is to fix this thing so I can drive it once in awhile to keep from putting a lot of miles on my new truck but it seems everything is working against me.

Here are some pictures of what I am talking about:

http://i1278.photobucket.com/albums/...ps3873b083.jpg
http://i1278.photobucket.com/albums/...ps3819f939.jpg

Has anyone out there ran into this or can anyone help me?