Topic: What's This?

[ClevelandKid]

Well after 50 years of owning my original unrestored 70 Mach 1 I decided to change my gas tank and sending unit as the sending unit quit working after years of running E10. The inside of the tank looks like a swamp. I took out the original mat and removed the factory tar shield that sets on the tank which I never had removed since I bought the car in 1973. This is what I found underneath. Some sort of hard particle board. What could this possibly be for?

[Bob Gaines]

Well after 50 years of owning my original unrestored 70 Mach 1 I decided to change my gas tank and sending unit as the sending unit quit working after years of running E10. The inside of the tank looks like a swamp. I took out the original mat and removed the factory tar shield that sets on the tank which I never had removed since I bought the car in 1973. This is what I found underneath. Some sort of hard particle board. What could this possibly be fore?

It is a insulator that helps add support (spread the load ) to the gas tank top half when the spare tire is cranked down and secured in place. It also helps keep the tire from rubbing through the trunk mat over the stiffing ribs of the gas tank.

[ClevelandKid]

Thanks for the explanation. My car as noted on the factory invoice that I got many years ago from Lois Emminger was ordered with a full size spare. 

[Bob Gaines]

Thanks for the explanation. My car as noted on the factory invoice that I got many years ago from Lois Emminger was ordered with a full size spare. 

I also see the board on space saver spare equipped cars.

[J_Speegle]

Earlier discussion on the same subject just different year

https://www.concoursmustang.com/forum/index.php?topic=11915.msg72111#msg72111

[HDAshmore]

Nice shape and markings