Hi

Do you still have the old mainboard?
As you should have some plastic spacer's there. (plastikkbein) who support your SCPPC. just take them out and insert them in the new mainboard.
If you don't have any, you can custom some old pc plastic spacers..but they are rare too.
But anything would work. just don't add any who short your SCPPC or mainboard.
Anyway you need to have something too support the SCPPC board. as it heavy. And at the end you will Get bad connection between CPU slot and SCPPC.
Buzz