Magnum Motor Rebuild Questions

If you got that 360 shortblock that cheap you are halfway there. You won't get a long block for twice that price. You should be able to get some rebuilt heads for a 5.9L on exchange basis cheap, then send the old heads off your engine in for the core refund. You should be able to get used parts from junkyard for ECM and injectors. In long run it should be cheaper than a full rebuilt long block. You said that the 360 was balanced, if it was internally balanced then just use your existing 5.2L torque convertor and flywheel. You won't be able to have engine built that cheap.