The big point has been given by RR, sealers are much better now, lessons learned are more available and many of the leaks are on engines in the car. Out of the car and on a stand that can be rotated where you have good light and clean habits, no leaks.
http://www.chevyhiperformance.com/techarticles/148_0401_fixing_leak_timing_chain_cover/viewall.html


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