Thanks for that info Midnight. I have heard of others using the High Tack. It seems like a good idea. I'll have to give it a try instead of just fiddling with the o ring in the groove and hoping that it stays in place while I try to put the cover back on.I have run into simalar situations with the O ring being to big, but not by 1 1/2" as you have encountered. I prefer the O ring to the flat gasket, and when they want to be fussy I find a few small dabs of High Tack evenly spaced around the groove will hold the O ring nicely while I fit the Derby cover. And I always wipe all gasket surfaces with Alcohol (either isopropal or denatured, saving the good stuff for myself) before any reassembly.
Jack that looks exactly like the gasket that I had in there. It is the one that I reinstalled. It's not leaking, thank God!Google Image Result for http://youroilshop.com/images/2541699C.jpg Here is the updated pancake style gasket