360 will not start, any suggestions?

The 360 in my Barracuda just won't start, no matter what I do. The starter will turn with the key, but it will not fire. I swapped the intake manifold from an Edelbrock LD4B to an Edelbrock Performer, because the LD4B cracked near the carb. It wouldn't start before I changed it, but I thought changing it definitely wouldn't hurt. I set timing back to TDC, and made sure firing order was correct.

The engine is a 360, date unknown. J heads, Mopar purple cam, Holley double pumper carb, compression and the rest of it unknown.

I have very strong spark at plugs.

I have fuel.

I have swapped parts around, with known good parts, including..

- coil
- ballast resistor
- distributor
- intake manifold (due to crack)

I also tried turning the distributor 180 degrees, but that solved nothing.

The car started and ran when I first bought it, but since then, it just will not start. It has a manual valve body, and I have tried starting in Neutral as well as Park, in case the neutral safety switch has some sort of issue. Not sure if that has anything to do with it not starting though.

Any ideas?