ive got a got a 205 cosworth block thats been bored to .5, and i wanted to know is it ok to use the standard crowns on the piston, ive got .5 rings to fit to them, but the guy who fitted my bearings to the rods say's that i have to replace the crowns with .5 1s to match the block and the rings,other wise there will still b play in the piston once fitted, and gases would escape and would damage the rings or maybe the piston. is he right in saying this

 

too right

 

You need new pistons pal.

 

thanks guys , picking them up monday