You need to rebuild that completely stock 440 before you start thinking about blowers and such. Just a good blueprint with a cam and valvtrain will get you over 500 hp. Plus it will get rid of those 850 gram cast pistons that don't like going 5000 rpm after fifty years. Just a solid blueprinted shortblock with decent pistons and a mild mechanical cam with if you could swing a set of aluminum heads, 600 hp if you can't but you can do some work on your own your looking at 525 hp and a engin that's not a bomb. It will run to 6500 with no problems.