Fuse Box Help
I had the same problem with my 67 fish. I think your problem may be at the top of the fuse holder box. You have to remove the 1 fat screw and pull the whole assembly down enough to get a look at the top. Carefully remove the plastic cover and look inside. Either something metal got in there or your existing tabs are touching each other possibly due to a wire that got pulled too hard. If you're really pulling 25 amps intermittently something's loose.
good luck.