There is a ticking/popping/knocking sound on my engine
I’ve been working in this project for a year now and swapped from a big block to a small block. Ever since I fixed the vaccum leak that I’ve been trying to find for the longest time I realized that the engine was popping( probably back firing), ticking and/or knocking. I’m not sure what it is and can’t really tell exactly what it is but sounds like it’s coming from the engine since there is no exhaust still it’s tough. I believe the engine is in the 80s and changed the oil a few months ago but haven’t driven it and only seems to do it when idling. Please help!
video of engine