the 2 wire block that's mounted to the coil bracket is a diode. the noise suppressor is located on the left hand strut tower where it meets the firewall and has 3 wires. it shunts the ground from the coil's secondary to ground through a capacitor/ resistor network which remove electrical noise from the signal coming out on the third wire that drives the tachometer.
if it is not grounded the coil tries to discharge through the tack which generally kills it.
the actual ground wire runs back into the harness and joins several other ground wires before terminating at a chassis point. that makes the actual answer of where the noise suppressor ground point is, internally, in the wiring loom for the front chassis.