You got a good response from Compass790, but I feel like adding two general comments.
790 mentions something lots of people miss, which is often expressed as put on the goo, position the part, wait for the goo to set, then torque it. If you torque while the stuff is wet you get no compression
and very limited ability to seal.
The second is that you can save yourself a lot of trouble in these situations by getting some gasket paper and making your own. You place the paper over the part to be gasketed, and then cut it by tapping with the rounded end of a ball-peen hammer for the curved edges. With just a bit of practice you can turn out a gasket in a few minutes. Having several thicknesses of paper lets you choose a thicker gasket that will seal easily in these low pressure situations.
Good luck with it.