This vette is the first one I ever butchered in my life as I want a driver and being a 74 with a 454 not of real value anyway.
One of the things I did was go extreme on was the insulation, the stuff I bought has 3 or 4 different layers of material, it was very expensive but I may have enough left to do your car. I'm sleeping at the plant tonight and Thursday night so if you are in no hurry, I can post a picture Saturday and name of stuff so you can check out.
I would cut you a deal on left over if you have an interest.
I will say this, 454's were noisy and hot inside to the point the air conditioner was totally useless but this car is a quite as any new car and heat is not even an issue.