As noted, the 1971 cars that received electronic ignition mounted the electronic control unit (ECU) on the left fender area in front of the windshield washer fluid container like the 1972 cars. The rear mounting bolt is about one inch forward of the washer fluid container mounting screw. The mounted ECU forward side hangs slightly over the edge of the fender edge. As also noted, if late enough, the fender may have dimples at the mount point. The following image is a 1972 car, but shows the mounted ECU:
View attachment 1716480355
The four terminal ballast resistor was mounted above where the previous point system ballast resistor was mounted. The following image shows the ballast resistor location:
This image shows a 1973 car, with the new ECU location for that year, through the 1976 models.
View attachment 1716480364
Note that the 1971 ballast resistor connectors differ. One side is a dual connector with white insulator like seen here. The other side is two single connectors with black insulators.
Chrysler’s electronic ignition, first appeared as a running production change after May 6, 1971 on 1971 models with 340 engine and manual transmission (Ref. Technical Service Bulletins 71-8-8 and D71-8-9), and introduced the four-terminal, dual ballast resistor, part number 3656199 and Electronic Control Unit (ECU), part number 3438850.