I didn't want to start a thread for this, but I really searched pretty hard and couldn't find this info. I am about to change oil on an M813 with the NHC-250 engine. I have the filter and oil, but I haven't been able to find the gaskets that go on the filter housing. If anyone knows which stores carry these and what the part numbers are I'm sure it would be helpful to many. I agree that a spin on fliter is a better solution, but the truck gets very little use. I hate to spend extra $$ for a spin on when it won't save very much time over the next several years. Information on multiple stores would be helpful since we live in various states. Thanks!