Car can start even in gear! What's going on?

I have no idea what you are doing. 85 Dart? No such thing. Neither is a 350.

As above and addtional.......

Run over to MyMopar and download the service manual. If it is newer than 73, there won't be one there. HOWEVER go to the wiring section and there are two-page aftermarket diagrams.........these leave out some details, but are certainly better than nothing.

Possible troubles:

As above........been modified and eliminated
Misadjusted shift linkage or damaged "rooster comb" in the transmission. Neutral safety on a 727 is a 3 pin switch ON the transmission. Center pin is neutral safety, it grounds in park or neutral

This ground goes up to the (proper) starter relay and grounds one end of the coil, allowing start signal from coil to activate relay