I plan on leaving the stock radio in the dash for looks- as it will still light up but will not function.
Here's what I plan on doing.
ANY DIN sized radio will fit into the dash, but you end up having to cut and basically ruin the OEM look, so my options for you are:
1. Install the radio in the glove box. You can custom build a trim plate of ABS plastic or mica that fills the glove box and looks nice, while retaining functionality of the glove box door.
2. You can also install a radio (preferably marine-grade) under the passenger seat and install a wired remote display/ controller in the glove box off to one side (so you have some storage in there still). This remote piece emulates the radio display so you can see what you're doing on the radio under the seat- and you can also add an RF remote control so you can control things from outside the car ,too.
Check out these parts from Alpine Car Audio or Aquatic AV.
www.alpine-usa.com
Search for the CDA9886M radio and M10 Marine Controller
In Aquatic AV, check out the CD3 and matching wired remote.
www.aquaticav.com
Hope that helps! I handle high end/ custom car audio so I can help you if you need any advice.
Chuck
Here's a photo of a 67 Camaro and 73 Road Runner I did. Similar set-up.