So, I have two vehicles that I would like edited beyond what Automation offers. One should have direct drive instead of 0.75 ratio in top gear, and the other should have a limited-slip diff before Automation allows them. Can I edit that in the files? If yes, then where to search for that data?
wherever your differential code is, usually under a suspension.jbeam (rear one) look for this line of code (or similar) ["differential", "differential_R", "driveshaft", 1, {"diffType":["open","locked"], "gearRatio":3.0, "lockTorque":1000000, "friction":25, "uiName":"Rear Differential","defaultVirtualInertia":4}] and change the value in red (don't use this direct example as the lock torque is really high, this is because it's copied and pasted off a bus.. using a high torque in a light car might cause instabilities with beamng)
usually in the engine.jbeam "gearRatios":[-4.5, 0, 3.1, 1.81, 1.81, 1.41, 1.0, 0.71], change the numbers to suit