is there a certain way to put the upper timing cover on. I.E. tightening the verticle bolts first, then the horizontal. I started the car finally today after the rebuid and it is leaking oil profusely where the timing cover meets the head. I sealed that son of a bitch with silicone- all new gasket including head and it still leaks- it leaked before about the same as it does now. Any thoughts would be apreciated. Thanks in advance- Chad