Rixter

Just to reiterate, I bought some 6x9's once thinking that was just the standard size. It isn't, they're too big. I just ended up buying cheap boxes and some velcro and have them sitting beside the normal speaker place. And it's been a while, but I THINK my door speakers are 6.5, and that actually required me to drill new holes to screw them in (Pioneer), so I think they're smaller than that (I'd measure first). And yeah, the dash are 3".

And just for my opinion, I also like Alpine speakers.

86 5.0L

3.5" up front
5x7 in the back

frdmstng1986GT

dont forget about the 5.25's in the doors in the 87-93(not sure if it was only with the premium sound or not)

notch5oh

3.5" dash, 4" wont fit i tried

5.25" door, but 6.5" will fit no problem

5x7/6x8 rear, its pretty easy to get 6x9's in a coupe though

vt89gtvert

5x7's in tha back of my Vert, but they mount behind the rear quarter panels, and are kinda useless.