Mine doesn't leak, period. I did take extreme pains to make every sealing surface secure. All though many do leak, it's really just a matter of putting it together right in the first place.
There are tricks to getting it right and some parts are tougher than others. Like stamped steel valve covers are harder to seal than alloy valve covers (there more stiff). Using 'just enough' silicone seal is better than using to much (on many levels). CLEAN surfaces are a must.
Now that rear main seal, I lit three candles, threw salt over my shoulder and knocked on wood before I started that one.
Whew, got lucky!
