Use a table ban saw to hack off the 340 piston crown .
the current price of the spacers just to hodge podge together a load of mismatched parts just reinforces what everyone has said about getting the right (off the shelf) parts in the first place. you'll be time and dollars ahead in the long run. and don't forget all this started with you're dislike of paying machine shop prices (to do the job right). :poke: