7.25 pinion seal replacement questions can't get the pinion nut off

This project is not going well. I cannot get the nut off. I cannot get enough leverage to break the nut free. I am using the plate tool with the holes recommended in a post above with a 3/4 ratchet and a 1/2" breaker bar with an extension pipe with a 1 1/4" socket. I even heated it with a propane torch.