1. The old speakers are different resistance from the original speakers

2. Most current radios are designed to fit into a hole that includes the on/off and tuning knob.

If you purchase a radio from a corvette catalog make sure it matches the old resistance or you will have less volume.  It will work but the volume will be a lot less.

You can get your radio rebuild and put in an after market CD changer I have seen them.  Or you can do what I did (only because I was taking the dash out for other reasons).

I replaced the speakers both front and back (should have gone with higher wattage speakers than I did).  Found a radio I liked and purchased a new bezel which I cut a new radio slot into.  That was easy to do as I just drilled small holes along the cut line then used a file to smooth it out the radio fit in and the speakers matched.  

Issues I found:

1. The interior of a C3 is bright and it make the radio dial hard to see.  Be mindful of this as I'm looking at replacing my radio with one easier to see.

2.  Got to low wattage speakers (should have gotten higher end speakers and may do that yet).

3.  Rear speaker brackets did not survive the trauma of being removed.  Be ready to may new ones as nothing you will find will be in better shape than yours. they were easy enough to manufacture.

It's getting tough to find stereos now with CD players except on the low end of the quality scale as everything seems to be going to MP3 type players with lots of options.

You may decide it's time to upgrade to a new bezel that takes a DIN-type slide-in radio...lots of choices there though fewer are coming with CD players as I said.  Save the original bezel and radio if that's important to you.  

Also, buy speakers that compatible with the impedance with whatever radio you buy plus of the quality that can handle the output power of that radio.  Install speakers that can't handle the output and you'll get lots of distortion at even low volumes...and C3's aren't noted for quiet interiors and any radio needs volume to be heard.

Feel free to PM me if you want more info.  

 

Kenwood KRC-2007 Cassette

Pioneer KEH-2030 Cassette

Sony XRCA300 Cassette

Pyle PLRCS20U Cassette

Pyramid 2706D Cassette

 

If you choose not to cut/modify or purchase a new bezel, RetroSounds introduced a new headunit that will fit into your existing bezel - looks original, but has all modern features including Bluetooth and a color changing faceplate:

 

RetroSound Model Two Radio - http://www.retrosoundusa.com/products/category/id/14

 

What I ended up doing was upgrade to an entire Kenwood matching sound system:

 

KDC-352U Headunit - purchased new DIN bezel & wiring harness adapter

KFC-4675C 4x6 Front Speakers - fit perfect into original location; no modification

KAC-1502S Amplifier - to power rear speakers; mounted behind driver's seat

KFC-6950S 6x9 Rear Speakers - fit perfect into original location, no modification

KSC-KW10 Amplified Subwoofer - mounted on rear wall

 

The headunit, speakers, amp & subwoofer all match and meet power requirements.  Placement of all the items leave room to store my T-tops in the rear compartment, and I didn't have to modify any of the original speaker locations.

 

 

Hope this helps...good luck, I hope you find the perfect sound system that you're looking for.

 

 

Lynn

You actually have some 8 track cassette?