With the front 31/2" speakers you have to watch the size of the magnet. Back in the 70's speakers didn't have the big magnets they have today. I had to open up my dash where they go to fit a speaker with a big magnet. After speaker is installed never see the opening anyway.
i plan to update the dash 4x10 and rear 6x9's speakers. my kick panels have a cutout for a 4"-5" speaker which i will consider adding giving me a 5 speaker system. can i get nice sound without an amp or subwoofer?
i also plan to get a stereo that will fit in the stock opening.