Perhaps clean it all up good and give it a good run, then check it out. As you mentioned, maybe your RTV job didn't cure well enough before you ran it. Re: Spacers; many have tried these and gone back to stock because of leak issues, but the phenolic spacers are more for helping isolate from heat transfer. Stock intake manifold gaskets w/ a coat of copper gasket spray on each side seems to work the best. I've tried twice but have had no luck using the rubberized cork gaskets. And yes, you'd do right by getting one of Needswings oil catch cans.