Does your '74 have the horn relay, or the old style without?
That's the year Ford changed to the relay for the Bronco, but not all early '74's got it.
Either way your starter relay/solenoid should be wired thusly%) :
1. Large left stud:
Positive battery cable.
Black (or Black w/red stripe) wire with molded ring terminal / fusible link
Yellow wire (also likely with fusible link (green end sometimes?) for horn relay power (If so equipped)
2. Small Left Stud (often marked "S"):
Small Red w/blue stripe wire
3. Small Right Stud (often marked "I")
Small Brown wire
4. Large Right Stud:
Cable to starter.
If yours does not have the horn relay, all connections are the same with the exception of you won't have a Yellow wire on the battery side.
Under normal conditions, these are the ONLY wires connected to the starter relay. But if going EFI then there is often a START SIGNAL wire connection from the EFI harness.
If you have additional power requirements, they can often be attached to the large left battery stud. But you run out of room fairly quickly sometimes and might have to resort to Plan-B
If you're replacing any of this stuff with new, for a few pennies more, go with at least 4ga battery and starter cables. Ford used 6ga, which is adequate under normal circumstances. But 4 is better in the CYA department, and costs just a little more. And 2ga is just "better" for the same reason.
Not required. Just nice to have when you really need it.
Hope that helps.
Paul