If you trace the brown wire from the connector on the distributor back to where it goes up into the main harness, and do NOT see the tach filter, then your car does not have one on it. The wiring diagrams don't even show it until '78.
As far as it not turning over/cranking, it could be a loose connection at the starter, a failing starter solenoid, a problem with the neutral safety switch(try cranking it in neutral)....there are several possible things to cause that. Excessive heat on the starter solenoid will usually damage them eventually, but so does time. I would suggest checking for voltage on the purple wire(small wire closest to the engine block) on the solenoid while someone turns the key to "Start". If you have battery voltage there, then the problem is the starter/solenoid. If you do NOT have batt voltage with the key in "Start", the I would be looking at the neutral safety switch/wiring, or the ignition switch/wiring. hth
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Joel Adams
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