In my 94 Blazer, I could have easily fit 3 ported, and your newer model Blazer seems more spacious. You should go measure the dimensions of your cargo area below the window line, so we get an idea of how much airspace is available.
My opinion, it's cuz a woman's breasts are used in private (or should be), like when a baby is getting drunk off the milk. Also, who wants to see a liberal 38 E that sags to the bellybutton?
I think that amp may actually put out about 1800Rms, WITH good electrical. They slang these at the flea market for bout $300. Try another amp (that you KNOW works), with those same wires to see if it's the wiring as well, or just the amp.