Sorry for the late reply guys, been busy with work and all.
Actually I had a video of the engine running before it blew and in person it sounded alright, but in the video there is evident knocking that I guess I didn't hear somehow. The entire time I owned the car the oil pressure would fluctuate a lot more than seemed normal, so my guess is the oil pump went out, causing one of the bearings to slip. The oil pressure gauge would just drop to zero sometimes, but giving it a little bit of gas would bring it back up. Should have fixed the issue when It occurred, but I got lazy. Also funny you mention swapping a sephia motor in, I actually got a low miles sephia as a replacement car for the time being. Unfortunately though, I do still live with my parents, and they weren't about to let me use their space to rebuild/swap an engine, and they forced me to sell my car. One day I will own another capri, as of when, I'm not sure.