Need to improve the sound of my system

[hgs_notes]

First off I have a 71, with a JVC head unit mounted under the front of my seat in an aluminum panel I made. I got the cab corner speaker speaker brackets from 73bigblock and installed a set of Infinity reference 6x9s in them. My cab is covered in fatmat. I thought the speakers would sound way better than they do. Granted, with the seat folded down it sounds much better, but it's just idk, muddy sounding. I'm adding in some 8" mid range woofers with dual voice coils from Audiobahn that are mounted in my old MTX speaker boxes.

I don't have an amp yet. I was wondering if I should add a port to the corner speaker brackets and add fiberfill stuffed in there and also in the enclosure boxes for my 8" boxes. Those will sit behind the seat where the gas tank was. I figured that adding power was not the answer if they don't sound great at lower power levels, but maybe I'm wrong about that.

I would like to add front speakers in the kick panels at some point and I know that will help a lot. But it will be awhile before I can do that.

Any ideas or recommendations are appreciated.