Crank no start after rebuild and dropping in known working engine

Rebuilt an engine and broke the oil filter mount on the upper oil pan during the process of removal. Used the broken upper oil pan regardless because I needed it... dropped in the engine. Runs and drives. Later I bought the upper oil pan replacement and pulled the engine to replace part. Dropped the engine back in and got too excited and hooked the battery backwards. Sparked a few times and then realized the issue, hooked up the battery correctly. Checked all fuses inside and out, and replaced blown fuses. Went to start car, cranks but does not fire up. When using starter fluid, the engine does fire up but stalls. Thought I messed up timing on replacement of the upper oil pan, pulled engine to re-time. Aside from that, I bought a used good running engine to verify issue, dropped in and same issue (crank no start). Thinking some electrical issues have not been resolved. Reviewed all fuses again. Tested injectors, they seem to be working as they are spraying as I crank.

I asked around and researched and all things point to a faulty fuel pump. I drop the fuel tank, and pulled the fuel pump out. Found debris on the filter and cleaned out, hard tested the pump for functionality. Also, I checked for fuel in the tank... I do have fuel in the tank because the others who had this issue had a no fuel no start issue. The pump seems to work. Re-assembled and started the car... still nothing... I have no checked the fuel line to verify pressure.

Current plans:
Buy new fuel pump to replace: the current pump is working but unsure about working pressure.

Please let me know if someone else has had this issue and fixed this.