I got the good tip on the web and installed this last summer.

it's at Lowe's home center and if you hit it right you can get it for $15 a roll. I think it took 5 rolls to do my 70 Superbee. Easy to work with, sticks like crazy and totally baffles the drum skin that is your floor don't listen to the critics that say it smells like tar. That's BS. I installed this stuff in 80-90° heat and it never smelled. I've read posts on other sites with guys setting their car out in 100°+ weather for hours with no odor. It's easy to work with. I used 1/4" overlap. Use a small wood or plastic roller to press it down. Sticks to itself great. It's ridiculous to spend hundreds of dollars on dynamat for the prestige of the label you'll never see.