Why did you swap engines?
Maybe old engine dumped some coolant into exhaust system
New engine heated up exhaust and was vaporizing the old coolant
Long shot but could happen
Simple, and FREE, test for a cylinder leak(blown head gasket or cracked head) is the Glove test
Cold engine
Remove rad cap
Remove over flow hose and plug that port; gum, putty, vacuum cap, ?? whatever
Lower coolant level in rad 2", more is fine but at least 2" down
Disable startup, unplug 4 wire connector on coil pack or pull Fuel Pump fuse or relay
Put a latex Glove over rad cap opening and seal it with zap strap or rubber band; OR you can use a balloon OR even a condom in place of the glove
Crank engine over and watch the Glove
If it bounces you have a cylinder leak
If it doesn't bounce then you don't
100% accurate test, unlike chemical tests, lol.
You may get a initial "bounce" when water pump starts to circulate coolant, but it won't repeat, leaking cylinder will be a repetitive bounce while engine cranks, each time leaking cylinder is on its compression stroke, a bounce, no mistaking it
If it does bounces then remove 1 spark plug at a time and crank engine over
When glove stops bouncing the last spark plug removed was from the leaking cylinder, put spark plug back in to confirm
You don't have to do this last part, if Glove bounces both heads need to come off to be tested and surfaced in any case, but some people like to know which cylinder has the leak so it can be examined more closely
Alternator bearing noise can come and go, but plan on it going, for good, sooner than later
How/why glove test works
Each cylinder in any engine has at least 140psi on its compression stroke, a blown head gasket or cracked head MEANS a cylinder has a leak into the cooling system, that's the definition of these problems, and why it causes over heating.
So the cooling system pressure will change each time the leaking cylinder is on its compression stroke, Glove bounces.
Even the smallest leak will show up, so compression tests are OK but not definitive for this, and chemical tests can show false positives from coolant contamination from other sources, which is why Shops like/love doing the chemical tests
You can have more than one cylinder with a leak, glove will bounce less, its noticeable, so keep taking out spark plugs to ID the 2nd or 3rd leaking cylinders.........if you want, as said once you know there is a leak doesn't really matter which cylinder, all need to be resealed and heads tested for leaks