Recently got an engine swap, and noticed this noise. (video attached) I did have an exhaust leak, however I got it fixed but i’m still hearing the noise. You can only hear the ticking when pressing on the accelerator, or when the rpms are high and they’re dropping.

 

What year and what engine was in there originally vs what's in there now? Any custom tunes? No sound when you're cruising at a constant speed? Does it get worse when you accelerate hard vs casually? does it do it when Hot and cold or just hot?

Sounds like preignition (coin in a coffee can rattle) that can be cause by several factors:
Wrong octane (too low) of fuel used - What octane is the car tuned for?
Bad Fuel - Add octane booster in this tank
Engine running too hot - any cooling issues you've noticed?
Timing too advanced - dial it back
Fuel too lean - Check your timing, make sure you have the right size fuel injectors for your build, adjust your tune and/or fix any intake leaks you may have.