It is 8Kg heavier overall, 4 Kg per side. My car, number 799, has alloy backing plates on the inside, not sure if the earlier ones did. I put some extra 40mm diameter load spreading washers on the inside as well. There are rubber gaskets fitted between the new brackets and the skin and larger anti vibe rubber bobbins than originally fitted. All in all, a better installation than the original exhausts. Ideal would have been to mount them to the chassis not the skin.
