The only Gm that came with that head unit is from a GMC typhoon. You can find them on ebay time to time but they are high rent somewhere in the 350.00- 400.00 range
might I suggest 94-95 s-10 blazer cd they match int perfect in are cars had one for years. easy to wire harness together and go. And thay ca be had for 50-100 unlike the ty radios
I have one EXACTLY like that and it came from a '92 Buick Roadmaster. The only thing you need to make it work in a GN is the wiring adapter so you don't have to cut any factory wiring and that's it!
There's place not very far from where I work who sells used car parts and I know they had one several months ago, but I don't know if they still have it but if you want, I can go back to ask for it...Just let me know...
Also there is one right now on Ebay under "Buick Grand National parts & accessories"...
'bye!
Claude