Originally Posted by bigray
sorry still just a little confussed.with the head off.the gap should be facing the valves or the piston..
ops:
I index them due to the high dome pistons and i don't want the piston to close the gap up. As you know most high dome pistons have a radius cut in the dome to clear the plug ends, but there is some power gains that can be associated with indexing. i don't know how much but all agree there is some. Indexing also allows for better flame travel, but to answer your question i think the open end should be facing the valves, but not everyone thinks this way. Here is a pretty good article by Autozone, which by the way sells the indexing washers, so does jegs,summit,etc.
JMO
Zip.
http://www.advanceautoparts.com/engl...#Power%20Gains