For my 88 k5, I installed the pioneer head unit that was in my 79 c20 pickup DD, and put a new pioneer with usb connection in the 79. To cover the holes from the old speakers in the back of the blazer, I installed a Polk Momo amp behind the spare tire holder, and a 12" Polk Momo sub and box that I made and covered, on the other side.
Next to the back seat, mounted low, are a pair of 6.5" Polk Audio Momo 2 ways. I removed the ash trays and mounted the crossover housings over the opening. The front has kick panels with pods built in. They are filled with 6.5" component Polk Momo speakers, and have an older amp under the passenger seat to power them. The crossovers for these are mounted on the trans hump, forward of the t-case shifter. The original speakers in the dash were replaced with 3.5" Polk DB series 2 ways.
I did all of the work myself. It was a big project to make it all look good, fit, and to hide all of the wires. The sound is great, but the ballance in the front is not perfect even with the kick pannels. The passenger speaker is aimed right at the driver's right ear, but the left speaker is aimed toward the center console. The best sound is from the rear seat.
Pioneer has been my favorite head unit for the last 10 years, since I was given my first aftermarket head unit. Polk Audio has great sound, and looks, at an afordable price. They do have high end stuff as well ($1000 per pair of component speakers for their top end car audio). For my home theater, I use all Sony individual components and then the Polk Audio bookshelf theater speakers and powered sub. My parents have an all in one sony theater with small speakers, that is only a year old. That thing sucks nuts. It is even too complicated for me (and I am pretty sharp with electronics), doesn't have an adjustment for bass level to controll the powered sub, and just sounds like crap. What can you expect for $600?
