First do a compression check!! f the compression is good it will be time to pressure check the manifold. The manifold is easy to check as all you need to do is plug one end of the water jacket and pressurize the other. Those points are where the coolant goes in and out of the manifold.
There are many links as to how to set up the manifold test with a "schrader valve", pressure gage and a bicycle pump.
Once the results of BOTH tests are negative then time to test the block.
Dave Neptune
