Originally Posted by
JDNSW
The later Series have the earth bolted to the top of the RH outboard part of the rear cross member.
Current flow through bimetal joints, provided they are tight, will not cause electrolysis. 'Electrolysis' (galvanic corrosion) will happen at bimetallic joints if they are wet, regardless of any current flowing through the joint. This can be minimised by contact being minimised by paint or other insulator, and by the use of galvanised fasteners, as with the original ones (avoid stainless).
The original ones were actually Sherardised, a form of galvanising that allows a more accurate profile to be maintained than dip galvanising. Instead of dipping the clean item in molten zinc, they are packed in a sealed container with zinc dust, and heated to just below the melting point of zinc for several hours. The zinc forms an alloy with the surface of the steel, the depth depending on the time they are cooked.
Unfortunately, Sherardised fasteners are virtually unobtainable today - it is hard enough to find galvanised fasteners, even if you are prepared to go non-original and not use BSF ones.
John