Cool Dave’s 1973 Dodge D100 Club Cab
Here's a couple examples using initial timing and advance from service manuals.
Here's a '69 with CAP/CAS with the gray dots representing measurements on an engine.
With the timing of TDC set at 700 rpm, the rest of the timing is in spec.
With 7*TDC at 1000 rpm everything is the same as as above.
BUT.
If the timing was set to TDC at 1000 rpm, the engine would be a lazy dog.
or
If that distributor was set to 7* at 700 rpm, the engine would likely ping under heavy loads, or even moderate loads once fully hot (long trips).
Finally here's an comparison of early non-emissions vs emisions distributor advance.
Late 70s early 80s distributor advances are probably different again because those had catylitic convertors.
Here's a couple examples using initial timing and advance from service manuals.
Here's a '69 with CAP/CAS with the gray dots representing measurements on an engine.
With the timing of TDC set at 700 rpm, the rest of the timing is in spec.
With 7*TDC at 1000 rpm everything is the same as as above.
BUT.
If the timing was set to TDC at 1000 rpm, the engine would be a lazy dog.
or
If that distributor was set to 7* at 700 rpm, the engine would likely ping under heavy loads, or even moderate loads once fully hot (long trips).
Finally here's an comparison of early non-emissions vs emisions distributor advance.
Late 70s early 80s distributor advances are probably different again because those had catylitic convertors.