No, I didnt let it cure for that long. Maybe that is the issue?

Need some advice please I have a datsun 1200 motor that I have fitted a new mechanical pump to. I replaced the plastic spacer between the pump and engine. I used gaskets as well as sealant, but there is still oil seeping through. I tried tightening more, but the spacer broke and I had to get another one. Tried adding more gasket, but that also hasnt worked. Anyone else had this issue? Thanks in advance