The 73 up engine harness is two piece. The part that plugs into the firewall is universal, the second half is engine specific.
The only difference in your case is that the coil wires and oil sending switch wires are going to be different lengths.
Unwrap that part of the harness and put the wires where you need them, then rewrap.
As for aftermarket wiring, you are miles ahead using even decent original stuff than rolling the dice on Chinawire