The 1982 380 engines were produced with a single row timing chain system that would fail after many miles of use. They would start to make rattling noise on start up and eventually will jump timing on the drivers side cam sprocket. These failures will ususally cause engine valves to bend, requiring that the head be removed for repair. The other problem these engines can have is that the head bolt holes in the engine block can be very brittle and start to pull out of the block when you try to re-tighten the cylinder head to the engine block, this requires helicoils to be installed for repair. You will also need to convert the timing chain and all the gears to a double row style, which is called a double row conversion. I do not know how much it will cost but I can tell you that it could be worth more than the value of the car.