New Cam Same Power

feed it some upper cylinder lube and see if the rings dont pick back up. Sounds tired on a 200K motor with a carb......probably a nice ridge in the cylinders and the rings just cant cope with the different diameter up there. Put the old cam back in and then save up for + pistons and a bore. Cheap would be to find the thinnest head gaskets you can find and try those, you could have some Fel-pro .050's in there when a Mr Gasket .022 would give you a little bump off the bat.