Is that Inca Gold (Y) or Sun Gold (G) on the Data Plate?
I like the Gold. I was looking for a Goldenglow Yellow 56 when I came across the Thunderbird Green.
Here is another useful site for general 55-57 info.
Dot Lang who is one of the "Grand Dames" of Thunderbird Lore and History has that site. She also has a 57.
The 351 looks great in there. Does it look like there were any major problems getting it in there? I would suppose the performance is a lot better than our old Y-Blocks. It still looks like a tight fit to add a booster on the firewall from what I can see.
Since the booster was disconnected were there also other changes made to the brake system? Does it have a dual Master Cylinder?
I see you have a '65 Vette also. I graduated from HS in 65 and always had a fondness for that year. Drop in a pic of that if you get a chance. What are you running in it?