I used the heating duct insulation because I was afraid of the smell coming from a tar based material. All though, the original crap I scraped off my '37 looked like some sort of tar base type sealer. Use a foam type insulation on the roof area and tar based in the doors and on the floor. I have seen the interior of my truck get to 135* when at a show, but then my truck is dark green. Get you a sample of the peal and seal, stick on some sheet metal and throw it in the oven. Then you will know if its going to stink
I bought what I thought was a peal and seal material from the local roofing supply. It was a tar base to seal the valleys in the roof. I put it under the fiberglass fenders to keep rock chips from forming. It was so sticky, I had a hard time getting it in place. It really looked good, till at I got it out in the sun. All four fenders worth fell off with in two hours after sunrise, as if there was no glue on it at all! Joe