The rockauto description says the gaskets are paper. The Mahle website (attachment) crosses 3680995 over to their part number J17829.
To be safe, make sure your old gaskets are the same material and roughly the same thickness. You don't want rear axle oil leaking onto your brake shoes and drum.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
