I used a double-layer of "boot"material(22"inner-tube liner),for my application. I re-built one back in the '80's,and it lasted until the truck,('60 Apache 60),got so badly rusted,that when you applied the brakes,the cab would shift and the gas pedal would jam to the floor! Wasn't long b-4 that poor tired old 283 threw a rod at a stop-light! Wasn't neoprene,but it lasted 10 years with about a million splits in that amount of time. I hauled a lot of building material,and roof tear-off's with that old girl.
