Mustangs (and other Fords) with automatic transmissions had a neutral safety switch controlling the starter.
Mustangs (and other Fords) with manual transmissions never NEVER had a neutral safety switch controlling the starter, not on the shifter, not on the clutch pedal, at all. It was perfectly possible to start any manual-trans equipped Mustang in gear. Including your 69 4-speed. Be careful.
Which bring up the question of what do those running at the Drag Strip do?
I am getting the Mach ready for a trip to the strip and looked over the
Street Class rules, It says manual trans cars must have a clutch depression switch for starting.
These cars were not come with one, So what are you Track guys doing?
Will I be turned away for not having one? I always start up in neutral anyway.
Only on automatic transmissions. This is the 69 4-speed back-up light switch. You see that red loop on the plug, connected only to itself? That bypasses the neutral safety switch circuit.