Rear Speaker Issue

[Khronik]

After reading alot of posts everywhere possible on rear speaker sizes and noone having a definite answer, because apparently every year and every option has completely different setups.... I pulled my rear speakers out and got this....

Rear Speakers 5INCH round (BOSE 109638 J)

Now questions:
Are the rear speakers, speakers or are they subs?
Is it possible to modify the top part of the plastic enclosure to fit something more universal? 5.25, 5x7, etc etc

[jona300zx]

from what i know you have the bose option which fits a 4 1/2" speaker snug... and the non-bose option that fits i think a 6". you can find the non bose brackets for sale in many classifieds i.e. craigslist, here, ebay....

[Khronik]

thats one of the speaker sizes I had seen on posts, but I took out my trunk interior and went to a sound shop

we test fit everything he had from 4 to 5.25

4 is way too small, and 5.25 will fit on top of the enclosure above the lip set for the factory speakers but looks like they would fit if I cut some of the enclosure but its plastic... if I put the interior piece back on it presses down on the speaker somewhat and no speaker operates properly like that

they are powerred speakers, they have a port and an amp for each

ill check out some classifieds to see if theres any brackets I could use

EDIT:
looking at sonicelectronix.com it shows this for all BOSE 90+ 300zx

Front: 4"
Rear: 6-3/4"
Front door: 4"
Rear deck: 6-3/4"

and shows this for all 84+ 300zx without BOSE

Front: 6-3/4"
Rear: 6-3/4"
Front door: 6-3/4"
Rear deck: 6-3/4"




I found on Z1 they have 6.5inch enclosures that dont come with the amp or speakers (also 4.5inch and 4x6), would the amps in my 5inch enclosures work for 6.5? im guessing it wouldnt be an issue? pull em out and put em in the other enclosure?