Swappin 318's

When I opened up my old 318 before I bought the 360, there was a bolt missing from the #2 main.
look for metal shavings in the sludge at the bottom of your oil pan.
take compressed air and blow through the coolant journals to get any crud out of there. Replace the front and rear oil seals too.

Nothing worse than finding that oil leak after all that hard work of installing it.