This is my 1st week of February 1973. Sometime shortly after GM changed to the single piece headliner. So 73 could have either depending on the production date. Roof structure is exactly the same
I don't buy into the temperature sensitive field coils. There is a whole other issue going on with so called hot starters not working. The weight issue is the large cast iron field case and large armature! 168 tooth flywheels measure 14".
I bought the ones that NPD sells and they are a complete joke. Car sat just like that. I called and they told me it would settle. It didn't and I changed the springs.
My first 73 was bought in 1984 and it had a Emblem. The emblem was wrong but it tells me that stuff got changed early. I don't believe the tall spoiler ever had a emblem. I am probably wrong but it makes no sense to have a Emblem on a 71 and not a 72 73.
This is how my bone stock 73 Z28 ammeter works. Everything is 100% OEM, even the correct Delco 37 amp alternator. If you have a non original electrical system,I recommend a volt meter.