For the head bolt tool go to Pep Boys or AutoZone and get the pack of 4 12-point (double hex) bits that slip right into a 1/2" socket. I think the 603 takes the 10mm bit. The bits are strong enough for the 50-70 Nm (depending on reference) plus 2 90-degree turns the 603 tightening procedure calls for. It's ~$10 for the pack.

Sixto
95 S420
87 300SDL