Well, you have a number of options. You can sell it all off and put an LS motor in it (cheap, ubiquitous and a junkyard long block can hit 400+ hp with just a cam swap), or you can work with what you've got. I'd limit the stock explorer short block to 6,500 rpm. Towards that end, for now keep the other parts, sell off the cam (it's going to be tricky to make it driveable anyway), and pick up something better suited - a split duration cam in the 220-225 intake and a bit more on the exhaust at .050. I would stay away from cams with steep lobes - hard on the valvetrain, and the performance seems no better than (if not slightly worse) than more conventional cams.
Such cams are plentiful in the classifieds. 380 hp shouldn't be too difficult to hit with your other parts. I'd bet you'd break even on the cams financially.
'84 LTD LX - 9.83 at 140.09. Whippled 365 SBF with a glide and 3.08 gears. Driven to and from the track 60 miles without even changing tire pressure.