[QUOTE=PMI;2279239]Just to leave a bit of real information for anyone else who pulls this up looking for the rear speaker size and installation information:
The rear speakers on the 3-door/hatch (1990 LS) are NOT in fact 6.5", nor will most 6.5 inch speakers fit, at least not if you want a drop in replacement to go under the existing grilles with no cutting or drilling. They are 160-mm (actually a hair less than that) w. three mounting screws. 6.5" should, but nevertheless does NOT fit into the drop in openings… why?.. because, the original speakers were a press-fit (!) in addition to the three screws.
A Pioneer TS-G1644R will fit if you cut off the outer mounting ears (dremel, etc), but it is not a great speaker, and does not come with a gasket.
I managed to fit a Polk DB651, after sanding the opening in the bracket under the stock grille. This is a better speaker to start with, and comes with a decent quality gasket. It does require for new holes to be drilled because the holes in the speaker basket do not line up with the ones in the bracket. The adapter bracket which comes with this speaker does not fit under the stock grille, nor inside the stock opening without cutting one or the other, and leaving air spaces… (Crutchfield claims the Polk speakers fit with this bracket - NOT!)
It looks like the Polk DB651S (s == slim) would be a better choice, and has mounting holes for an x3 hole pattern, but I just was not willing to return yet another set of speakers to find out.
Apparently the Boston Acoustics has a set of comparable speakers which are supposed to be a more direct fit, but I have no way to confirm that.
There are pre-drilled holes for a 4-screw mount, with a radial offset, but those may not match every speaker.[/QUOTE]
nice info. whats the front info?