You'll get alot of diff opinions on this. I dont feel that a metal gasket is pliable enough to seal 16 in hg of vacuum. Alot of times the added thickness of the paper will throw off the alignment & the bolts wont line up. My preference is to use the valley pan with #2 permatex,the brown goo in the toothpaste tube. It stays pliable, especially with the diff expansion rates of iron & aluminum. works for me.