Hey!
Hope I'm in the right place for this.

About 2 months ago I bought a 1984 5.0, lately it's been idling pretty rough and intermittently stalling so I figured I'd change the spark plugs to see if that would fix the issue. While I was at it why not change the wires, rotor and distributor cap since they're pretty cheap anyways, but I ran into a bit of an issue when it came time to replace the wires...
I have reason to believe whoever changed the plugs last might have messed up the firing order:
1) The plugs I pulled weren't stocked and weren't gapped right, all had different gaps
2) Wire lengths didn't make much sense, i.e. plugs closer to the distributor should have shorter wires, plugs farther away should have longer ones, they seemed mismatched.
This makes me think that whoever did it last wasn't too certain on what they were doing and might not have done it properly, especially with regards to firing order.

Here's my issue, firing order for a 1984 5.0 is 15426378, firing order for a 5.0 HO is 13726548, and the plugs were wired in the non HO configuration, however my air cleaner housing says the engine is an HO, and according to about half of the VIN decoders I've looked at, my engine code (M) says it's an HO engine as well. As of right now, I'm hesitant to run the car as is, and I'm also hesitant to re-wire the plugs to the HO configuration as they weren't in that order when I got the car.

Hopefully someone with a little more knowledge and experience with these cars can help me out since I'm sort of at a loss of what to do here and this is my first time doing more than super basic maintenance.

Thanks!