Originally Posted by djfllmn
the MACH head unit is a pretty good one
I second this. I have had a Mach head unit for years and it works great for stock ( it does play mp3 cd's). I'm a stock kinda guy. I try to use only parts that have a Ford part number, except for the Hurst shifter. Anyway, I recently upgraded to speakers from a Lincoln and Mustang. I used the ones that have the sealed enclosure built around the rear of the speaker. They are 2 way with separate tweeters. The speakers really improved the sound of the Mach unit. I was very surprised.
I needed to trim the rear openings some for the Lincoln speakers to fit. If I would have used the Mustang speakers in the rear, I probably would not have needed to trim the metal openings. If you start looking into the different speakers, you will see the difference in the enclosure in the different speaker versions. The Mustang Mach speakers have a more curved rear enclosure which will fit better. I realized this after I already trimmed the rear openings. Oh well...