Todd
A few years ago I installed 1:25 to 1 ratio rockers on my 1.9 WBX.  They fit fine under the leak free factory valve covers.  This summer I installed a pair of aluminum EMPI valve covers.  I now have the same problem as you, the new bails seem weak compared to the factory ones and the new covers leak.  I tried bending the new bails to get more pressure on the valve covers,but this did not cure the problem.  Does anyone have a cure, the aluminum covers look cool but the oil leak does not.
George
'85 Westfalia 

I installed a set of aluminum valve covers from Gene Berg.
I was told that these were needed to provide additional clearance for
the new rocker arms. Unfortunately they leak like crazy!