So I am doing a top end on a Ms 660 I have. The story goes, I got a 660 on eBay that looked like it was all OEM but it was OEM parts on a china case with a china top end. As expected, it failed. Crank bearing took a ****, so I bought an OEM bottom end off eBay. No crank play and pressure tested with old china cylinder and it passed, so crank seals are good. I got a meteor P/C kit for it, and I'm having a helluva time getting it to seal at the base. I'm using Permatex Motoseal since I deleted base gasket. Squish measured at about .025 after base gasket delete. That should be a safe clearance right? I have read you really don't want much less than .020. Anyways, I keep getting air leaks with this setup, even tried using a new stens gasket, but still it leaked. My question is, there is a sort of lip around the cylinder base. Is it advisable to get a piece of glass and sand this lip off? If I do, I think it being flat will help it seal better. Will recheck squish after that, may need to use a gasket again, depending on thickness. I just don't want to sand this off if it turns out its there for a reason. Attached are a couple pictures I took of it against a straight edge. Hopefully you all can see what I'm talking about...TIA