Those four holes are there to prevent a leaky diaphragm from flooding the crankcase with gasoline in case of a failure of the gas pumping part of the pump, which is what has happened.
Jerry
Friend in h.s. "fixed" his leaking pump on his Nova by whittling stick to plug the hole. All good until the oil pressure light came on. I replaced his pump, drained couple gallons, new oil & filter. Ran until he crashed it. 283 4spd.
