HEI upgrade, wont start (no spark?)

Be fair, the ebay seller was not dishonest. I don't read "HEI" anywhere in the ad.
Rather than turn-over your engine constantly, remove the distributor and spin it by hand. Wire-up temp w/ alligator clips and use a multimeter to verify supply voltages. Use an inline spark tester to verify spark ($3 Harbor Freight).

If you haven't wired the Mopar box into your car yet, I would not use it and instead use the distributor to trigger a GM 8-pin HEI module & coil (85-95 V-8 trucks or TrailBeast' kit). That lets you eliminate the ballast resistor and get a stronger spark. Look real close at the 2-pin bullet connector for the pickup. I have found some on aftermarket Mopar pickups that weren't quite right. The male terminal was too short and didn't make solid contact. Those are used in appliances as well, but the Mopar ones are slightly different, and the Chinese haven't figured that out yet.