At what reduction in weight to the con rod, piston assembly would be a benefit to get the crank re-balanced(ie- give the machine shop the new bobweight for everything the crank will swing)

LAter <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

Any more then 3 or 4 grams I would get it rebalanced. You have to remember that 3-4 grams at zero rpms is like several hundred pounds at 6500! Nothing worse then a mis balanced engine. Premature wear and potential to loose some ponies is not worth it!

What are you changing from??