I have a 99 Durango, recently a mechanic said he swapped motor from the 5.2 to a 5.9, I suspect he is lying but dont know how to prove it.

My old motor had a click from the block and burned about a bottle every 2 weeks, new (supposedly new) motor has same click and burns as much oil.

Is there a way for me to see if this is 5.9 or 5.2?

Also anyone know where the heck the serial on the block is? I cant seem to find it anywhere.

 

It should have either 318 or 360 stamped on the side of the block (lower driver's side maybe)