just got a new tappet for my zetec, now the old tappet when you looked inside the (collet?) the thing with the spring was small now this new tappet its larger its still got the spring inside it, its just larger, will it make any difference if i fit this new one or does it have to be the right size?

 

thanks people!!

 

they did do a modification to them is it the tappet your changing or the valve spring?