Small block keeps blowing the oil filter off?

What is it clogged with? If you dont clean out the pan, the new one runs a very good chance of having the same problem. If it's gasket crud, pull the intake and make sure there isnt more stuck up top. If it's valve seals, replace them and clean out the pan. They can lock up the pump if they get small enough and hard enough to get thru the screen. I'd rather do it once than several times.