340 Spark Plug Wiring Schematic

I wanted to replace the spark plug wires on my 1970 340 Swinger that I recently purchased with little history. I found that 3 of the wires were too short from a Mopar OEM set for 340 engine. Upon further investigating and research I have found part of the problem but the remaining part has me baffled! Seems that the #1 piston - the one on drivers side closest to fan - is connected to the distributor at the 12:00 position. All diagrams that I have seen and comparing to my neighbors 69 340 Swinger, that the #1 piston should be connected to the distributor at the 6:00 position. Car runs fine this way but how is that possible? Is the timing chain installed incorrectly or how can it be fixed or just leave it alone?I have attached a photo of my incorrect schematic for you to review.

Big Guy's 340 Spark plug wiring .jpg