Spark Plug Wires - Proper Assembly with Acorn Nut and Washer

I started down the spark plug path because I noticed all the spark plugs were rotated 180 from the firing order shown in the manual.

Once I fixed all the plugs (which fell apart as I was unscrewing them) the car would not start. Now before I started fixing the firing order I was able to get the car run nicely up to about 2000-3000RPM. But then it started backfiring, especially during WOT.

What I found out is the distributor is rotated 180.

Does anyone know if you can loosen the distributor and rotate it 180 without having to remove the entire intake manifold? I don’t think I can get in there to release the distributor hold down bolt unless I remove the triple SU assembly.