you won't be able to fit 4" pioneers in your dash unless you "adjust" the hole. I had a set of 4" alpines from my 89Z that fit perfectly in it, but they wouldn't fit at all in my 91. lol, so i had to go out and buy some new 3.5" Clarions 
My Clarions sound way better than the Alpines anyways. and Audiobahns are way better than Pioneer. Ebay is good as long as you buy the stuff new with a warranty, i just bought 2 Audiobahn 1200Q's off of ebay for $200 bucks brand new in the box and they sound insane 8)
My Clarions sound way better than the Alpines anyways. and Audiobahns are way better than Pioneer. Ebay is good as long as you buy the stuff new with a warranty, i just bought 2 Audiobahn 1200Q's off of ebay for $200 bucks brand new in the box and they sound insane 8)