rod knock ftl
Time for a full rebuild. Either they fucked up the oil change or your bhg got coolant into your crankcase and got things real hot because of the friction and wore out the already worn bearings. It was inevitable if you have been hearing knock for a while. When you hear a knock it is bet to shut it off right away and get it towed to a place it can be torn apart. The more you drive on it the less salvageable the parts get not only on the bottom end but the whole engine because all the debris will get into the head and cams etc.