If there are no numbers on your Piston top or bearing shell backs I would be worried about the quality of a product that is not clearly stamped with it's size.
If you are not familiar with measuring accurately with a Micrometer, take your engine along to a local engine builder.
Is there any writing stamped on top of piston, e.g. STD, 020, 030, etc. should be similar on bearing shell back, any pics, Regards Frank.


QUOTE=Themadmob;2375819]Hi all ... I am about to pull apart and rebuild a S2 petrol engine and I would like to know how you check if the engine has been rebored or is the bore still standard ... If the big end bearings and main bearings are still standard size ?[/QUOTE]