Hello everybody. First post here, I thought this would be a worthy contribution to the library of information contained here. Thank you all very much for a thousand answers I have found on your site. I have been restoring a firechicken for the last year and have relied on, and benefited from information I found here.
The dash carrier on the 69 is a difficult piece to fit a modern single din head unit into. It was molded at the factoy to house the original style radio. In all my research I have not found a solution, so I was forced to handle the issue "in house".
The short of the long is, I made a vacuum former out of stuff I had laying around. I used the household vac and the kitchen oven to heat and form a piece of abs into the shape I needed. I shaped a piece of pine with a chop saw, table saw, and sand paper, to create the mold at the dimensions I needed. (Minus the thickness of the plastic). The whole thing took me..over a year thinking about, researching, and trying different install kits..and one afternoon.+3 beers.
The result was exactly what I wanted and I am happy to share them here. I am attaching pics, and eagerly waiting for opinions and criticisms. Proud to be a member here, and I am looking forward to posting more as my pretty bird rises from the ashes.

Nicely done and welcome aboard.

I hope you kept the mold, I'm sure others will be interested.

I did, and I would be more than happy to help out if somebody wanted to give it a try. It was a nerve racking job cutting into the replacement dash carrier, but if you are careful, it can be done. Important to note that you need a small lip inside the silver detail ring for a place to glue the part to. I also reinforced the bond from the inside with gorilla epoxy. Be careful to preserve the mounting studs for the heater controlls at the top of the removal.

Very nice job...Welcome aboard!

now you will have to cut the metal part of the dash to fit the radio in

Good observation there. Thank you for pointing out that. The previous owner had already done that to the car, so I did not have to do that. I was trying to Improve the work that I inherited. Here are a few picks of the dash as I got it. Pretty crafty fiberglass work. With the stereo installed in that hole, the screen baisicly pointed at the floor. That is what prompted the piece I made. On a different note, I haven't actually installed the new carrier, so I still might encounter an issue there. Luckily somebody already took the knife to the metal in there, so if I do end up doing any additional trimming, I can skip the guilt.
I understand that some firebird owners might not be intrested in cutting into the dash supports to upgrade the stereo. There are several things that I would have done differently, like not cut and tape the factory wiring in multipal locations. After 50 years, and a few diffrent owners, the car was showing its age. I ended up installing American Autowire full update kit, and Dakota Digital VHX gages. There is now not a single crimp connector in the car. Not an inch of tape on any of the wiring. I also upgraded the radiator and added electric fans. Anywhere I needed a crimp, I extracted the wire from whatever mating plug I was working with, and ran full length wire from clip to clip.
Thank you kindly for your very smart observation.

Pictures didn't take or something, cant see them.