6. Cylinder duster is now a 340 ignition issues wants to start when you let up on the key

Sure. That's in the wiring diagram linked here
https://www.forabodiesonly.com/mopar/threads/ignition-help-needed-stumped.499412/post-1973584740Download the pdf.

Brown is the feed.
The negative going to the ECU was probably black with yellow stripe.
The important thing is that the negative connects to the correct position on the plug.



Here's a '75 that doesn't look modified with slant six a/c and maybe cruise control.
VR is on the fender like yours.
The sticker on the fender is probably the vacuum diagram.

https://www.forabodiesonly.com/mopar/threads/1975-4-door-dart-part-out.366291/
and another
https://www.forabodiesonly.com/mopa...his-could-take-a-while.447399/post-1972703033