'36 221 - rebuildable??

[jers36]

I was reading your article about the different numbers on your engines heads. I have a 36 PU and it has the same numbers 68-6049B and 68-6050B. I have seen other 36's with the same numbering but I don't know why. What really got my attention was when you were trying to define if it has insert or babbit bearings. I think my engine is original to the truck but of course I have no way of knowing for sure. My engine has large block off plates where on newer engines the water pumps mount on the front of the block. Is this a definite sign that you would have a LB engine?