Got Shell 93 Octane and now barely idles 1973 Dart 340

Pretty nice offer for someone who has zero liability on a classic car 8 mos after the sale.
Wonder why.
I think if I were you I would just pull that 340 and stick a basic 360 in it until I got the 340 done.
At least you could drive it.

When I bought the car, part of the negoigated deal was to have it trailered to the Chicago area at no additional cost. He knows that I don't have the means to transport the car 6 hrs one way and to pay for it myself would probably be $500 each way, plus my time off of work. I think he is calling bluff and would the bare min. just to get it to run.

I am looking at a 360 classic cruiser build by MRL Performance for now and then put the 340 on a stand in my garage, so that my son and I can work on it and see what went wrong.

It all sounds suspicious or questionable.