Originally Posted by Tig
Grounding both heads will help with electrolysis when it's running, you have a basic battery exchanging ions through the coolant due to the dissimilar metals in the heads and block. Adding an easier "path" for the electrons flow will help reduce the electrolysis effect on the head studs,head gasket fire rings etc and technically,you get a better spark. I run an earth from the batteries in the trunk to the block, the starter motor turns the engine over a lot easier. Sure it adds weight but your ignition system will thank you. twocents
EDIT: Some coolants also have corrosion inhibitors which will help also but not all drag strips like you to run anti freeze / summer coolant


I am not sure how much current is or how long any current is actually running thru an Alum Head. as AndyF mentioned its effectively a bus bar, and I can't believe any current induced into the head connection "likes" the coolant instead of the massive amount of Alum to flow thru. I believe electrolysis occurs and is a concern rather independent of any typical grounding scheme, and I have yet to read anything that makes for a case otherwise.

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.