I spotted these as well. Seems that not all of the parts from the kit are there going by what I saw on the Ferracci site. I think that some balancing work may also be required as these pistons are heavier than the standard ones. Have to say I am tempted but have no idea what to expect to pay to have the work done when supplying these parts. I hear parts and labour would be around £2300 at most specialists. Anyone know any different?