2005 Forester x manual, swap with engine from salvage auto. Changed headgasket, timing components, seals. Really loud knock sound, I cannot tell if it’s a rod knock, piston slap, tensioner or lifters. Any ideas?
It really is so hard to say as many of the noises from potential culprits are so similar. The deeper sounding knock does sound like bottom end, but hey, that's just what it sounds like here. Tappets / lifters sound noisy normal to me.
I would seriously recommend getting a stethoscope which will help you narrow down where the noise may be coming from.
What's your oil consumption like?? That usually is a very good indicator.