Stereo System

I just got a 2003 crown vic. Im taking out the stereo system from my 69 Lincoln and putting it into the Vic. Im reusing everything. But what I dont know is which exact adapter I need for the dash? They all look like theyll work. I have a standard Pioneer stereo.

And I have Rockford Fostgate amp/speakers but I dont know what size the door speakers are in the front of the vic? The front speakers I want to put in are 6.5's. Also generally can tweeters be installed in the door ?

http://www.supermotors.net/forums/thid-8949-stereo-system#40327

You can buy the harness at any local electronic store or maybe walmart. I believe you would want to put your highs in the dash to reflect off of the window or the small tweeters that mount on the inside time between door and window. As for the size you'd be best off pulling your old speaker and seeing what size it is. Door speakers are often different