Nobody said it can't be done...BUT would be a lot easier if you had the whole donor vehicle for wire harness/possible ECM/PCM and ALL the different coolant hoses and little "tidbits". Note that a possible ECM/PCM swap would also involve a probable "flash" to link in with the rest of the electricals. Physical replacement is not the "touchy" part. And be aware...the 3.5 has it's own "special quirks". Good luck and let us know how it goes if you make the swap.