stupid GM HEI conversion

some ideas needed here..ok, i need a way to fasten the HEI/heatsink to the firewall so it will be grounded to the firewall. (It is just taped up there in the Pic)


Tried to drill holes and secure it with these sheet metal screws but they wouldnt tighten up, i guess the firewall sheet metal is so thin it cant tighten down, just keeps turning.


and no, i did not drill the holes too big..