Pshhh What da F@( !!!!!!!

I chanced my oil on my 77 911s this morning only 2 discover that my oil was deluted with fuel and thin as water. Also 3 weeks ago I had some mech. toon my K-Jetronc & I personaly feal that my feel mixture is 2 rich, although it has none of the acompanying signes like fumes from D exost or change in colur of D fumes I also checked my spark plugs & they seem fine, so then D questin comes WHERE DID ALL THAT FULE COME FROM my diagnosis is D pistin rings but can some one else share their opinion, or have suggestions how to do any tests to check this without taking my block apart?