am i having a problem?

I recently had to have my ac compressor and accessories replaced on my 96 gt and now I finally have ac... Good thing I'm only home once a month to drive it... But anyways, my car runs like a champ for what it is.. but you let me kick ac on regular ac and the third blower setting.. and its like I just took 4 cylinders away... It's a bad loss of power when I kick the ac on.I know you loose a little but not this much.. is this normal or is it something I should worry about?

I apologize for the lack of info. I do not have any work done to the motor, its 100% stock 4.6 sohc. I just notice a loss of power as soon as I turn ac on. The power loss is more than I've ever encountered. I can take a large hill by my house in 5th with little bog but now that I have ac.. I have to drop to fourth and it feels like its really working to stay at 55 mph. I don't really spin the tires, so I could tell ya if I can catch second with ac on. To be honest, i bought my ac kit from eBay. They aren't genuine Ford parts but the mechanic said everything seemed top notch parts. I know I keep smelling a weird smell when my car warms up.. its not like any fuel or oil smell I ever ever smelled... But it didn't just start.. its been smelling since u bought it.. I know I smelled the same thing on my 96 v6 Stang back in the day... I'm just trying to throw as much info a possible.