Depends on what is runningoff of that fuse block. The wire is 14 ga SAE, but when running goes though a bunch of connections and the start switch. Not sure but probably not fused - which is both good and bad. Less resistance is good. No protection for non-engine items on the engine circuit is bad. There's probably a fusible link on the feed. if so probably two sizes down from 14, which would be 18 ga. A CD ignition box like an MSD pulls very little current for its internal relay so that's why I felt confident saying hook it up even with the 1/2 ohm resistor in place. But if its running electric fans, fuel pumps, etc, then got to add up the amp flowing through those wires and fuses at running voltage (14.5 V). Add that to the field current draw, turn signals, wipers, and anything else that could be on at the same time using that same feed fusible link (to J1) and the branch (J2). Wires in the engine compartment will get hot so have reduced capacity.