91 gmc sonoma speaker

I've got a 91 Sonoma extended cab that the previous owner completely hacked up the stereo wires...I've got a bit of work to do to get the head unit installed, but for now my question is... How do I attach the 4x6's in the dash to the speaker grille? I know the speaker goes over the posts, but how do you secure the speakers to the plastic posts? I'm guessing there used to be some sort of nut because I can see a groove on the post from something...but nothing is there now. I'm going to use a washer on both sides of the speaker but I need a way to lock it down tight so nothing shakes loose. Anyone got any helpful hints or ideas? Also...I'm planning on using the same type 4x6's in place of the 4x10's in the back pillar...just going to make an adapter out of MDF i think...anyone sub something else into the 4x10 housing (4" or 5 1/4")?

use some speed clips and some piercing screws and make you own holes. I would use some infinity reference 4x6's which are actually 4x6 plates with a 3" speaker and a small tweet.To save some time with custom work this is what i would do. But I also have a bagged 89 s10 with 4x6 plates up front and 5.25 comps in the rear.GLrtfm

spookiestylez wrote: use some speed clips and some piercing screws and make you own holes. I would use some infinity reference 4x6's which are actually 4x6 plates with a 3" speaker and a small tweet.To save some time with custom work this is what i would do. But I also have a bagged 89 s10 with 4x6 plates up front and 5.25 comps in the rear.GL

forgive the noob question but what are speed clips and piercing screws? got any pix of your install? Are the 5.25 sitting in the stock 4x10 location? Did you fab up adapters or make a housing for it? I'm just using Sony Xplod 4x6 4-way for the dash right now...having no stereo is killing me...I need to get something in fast and cheap.