This is for you guys that know Harley model history. I am looking at an 80's model Low Rider. Its got a shovel 80" motor. Has a huge stock air intake cover with "80" on it. The original model decal is still on the downtube. It says "date of manufacture 8-80". The VIN# starts with HD then numbers. The last two numbers are 86. Here is where I am confused. From what I read in Harley books this is an FX model and the serial # should start with HD F for FX model, then numbers in the 3-7 position and the model year in the 8-9 position. So is this an 80 model or an 86? And is it an FX? Hope someone can educate me on what I am looking at. The owner knows nothing because it was passed to him through family. Thanks