i dont know what truck you have, but I think i only paid $14 dollars for my rear rubber from Carters. Considering that an old one gets hard with age and yours is already rusty and dirty, I wouldn't even think twice about buying a new flexable one.

Jeff
1947 Chevy 6400 2-ton
In the Gallery
1953 3/4-ton
In the Gallery
It was fun while it lasted