I bought an 06 impreza for dirt cheap. Needed head gaskets, an easy enough job. But im thinking the motor is cooked and needs a bit more rebuilding than just machining the heads. \n\nI'm having trouble finding a suitable ej253 at a reasonable price, the scrap yard has a few ej251s that I can get at a reasonable price (01 outback). \n\nIf I do go ahead and throw an ej251 into the impreza while I work on the ej253. Will I need to swap the heads? Or just the intake manifold/wiring harness. Will I need to swap the ecu?