1973 plymouth duster 340 h

I found this car on craigslist. The guy selling the car says it sounds sluggish when you crank it almost as if the battery were low. The car doesn't start. He replaced the battery with a higher cranking amp battery and got a new starter. This didn't fix the problem, he then decided to change the wiring harness and since has not been able to figure it out so he decided to sell. The car still does the same thing. He also mentioned he tried a few other things I can't remember all electrical.

The car looks great but my concerns are that the problem could be mechanical and not just electric. Could there be an issue where the engine doesn't turn over smoothly causing it to sound like a weak start?

I'm going to check this car out on Saturday anyone have any advice as to what to look for. If it's a wiring issue I don't mind but if it's a mechanical issue with the engine then I'm not interested.

Thanks

 

I would assume it needs major engine work

 

That's what I'm thinking, from what the guy is saying something doesn't sound right. Any way to know or check if it's a mechanical issue without getting to involved?

 

It's possible the cables are just mega corroded. I've run into this several times personally.

 

If the timing is over advanced, it will not crank correctly. Possibly the distributor advance mechanism is stuck full on?

 

I would pull the plugs and turn the engine over by hand... with the compression released the engine should spin fairly free... if not you may have a major issue with excessive internal resistance in the motor.

Is it Auto or manual trans? Could be some kind of powertrain issue further down the line adding extra strain to the starter?