URGENT help needed please!? Where is the engine casting number located on a Mopar block? The Jeep is a 1991 but we have just figured out that the engine had been swapped before we purchased it. Now we have no Idea of what year the engine is! I was advised by another forum the following:
"Take a look at your block on the passenger side right near the distributor. There should be a tag welded on with a 6 digit casting 'code'".
I went over the whole block and found these numbers on the block right near the Distributor as as suggested. The only number in that area of the block is: 107MX03 this is seven digits!! I am starting to think that it's not even a jeep engine?