Just talking about this today. Heavy dynamite is good for heat and noise suppression, they also do a ‘foam’ that is self adhesive and goes over the top of the heavy dynamite. The guy I was talking to did this in his shoebox ford and really rated it, ‘like driving a rolls Royce’ were his words. He used the thickest foam, and cut channels in it to run wiring.
The dynamite ‘lite’ on the other hand is rubbish for street cars if you are doing it for noise reduction, as it’s a race car product, designed to keep heat out, noise secondary. Non of its cheap tho.