[572Camaro]

I watched the video.
My guess is you have too much ignition timing advance during cranking.
Please please put a timing light on and check during cranking.
My guess on your application is you want about 15-18 degrees btdc while cranking. That means you want 15-18 degrees between 0-400rpm.

I have a F.A.S.T. fuel injected 572ci 68 Camaro.
I completely shredded my flywheel when it backfired through the intake when I had cranking timing set at 22 degrees btdc.

Please don't do what I did! Ugh.....,

Keep us posted. You have friends you've never met who care!