Just pulled the tank out of my 72 Dart Swinger to get a small leak patched and the tank sealed. There was no mat on the top of the tank. Did these cars have them? If so, where can I get one?

Not so sure that ALL of them had the mat but in most newer cars that I have worked on, it was just tarpaper, the same stuff that is under your shingles on your house. That oughtta ba e cheap/easy find. Heck, go with a double layer for extra measure!! (real expensive, will probably break ya)

Hmm, Maybe it stayed stuck to the top of the tank and you didn't notice it? They aren't that thick...

Sound deadening sheets would work well here too, dynomat, brownbread, or any of your favorite brands. You can get the same thing in rattle can form at your local auto parts/hardware store as well. Just make sure its throughly dried before you install the tank back in the car, otherwise you've effectively glued the tank to the car

If you really want to get picky, I believe I saw a "correct" pad at year one, but that was a while ago.

Just pulled the tank from my Duster today. It's nothing more exotic than a simple piece of roofing felt, just like Volaredon said. Go by a new house under construction, after the roof is installed, and get a few scrap pieces from their trash bin.

Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

If youre going to use roofer's felt, Id go with 30lb, it's nice and thick. Also a great product to use for sound deadening is icedam weatherproof membrane, also called ice & water shield. It is very similar to dynamat, but without the tinfoil coating on the outside, and the heavy price tag. Just peel & stick. Dynamat is actually a very superior product, but for what you want to do, this might be more cost effective.

_________________
I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Dynamat is expensive, but there deffinately are much cheaper and functionally equivalent brands. Not all versions of dynamat (and other such brands) have foil on one face.

Who can hear the tank over the engine?

_________________
My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.

Well the goal here I believe is to protect the tank from chafing against the frame and straps, but roofer's felt does provide some sound insulation so you can't hear the sloshing of fuel in the tank as easily after youve shut the car off.

_________________
I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I was just kidding. I replaced my tank a while ago because it was rusting all over the palce and on the new tank I put a ton of sound deadening stuff to prevent scrape and rust. I can't remember if there was a sheet there... probably stayed stuck to the car.

_________________
My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.