3.5 gas to 3.5 flex interchange
 

Hello, I have a 2010 impala with the regular 3.5 V6. It is not flex fuel. It recently started knocking and I have found shavings of metal in my oil when I change it. I plan to replace the engine with a low mileage used engine out of a wrecked car but I am finding it hard to find the regular 3.5 V6 version almost every impala that I find has the flex fuel 3.5. Are these engines interchangeable at all? I realize I may need to change intake manifold, sensors, etc. but are the block and heads identical? From what I have found I could also get my engine from a 2007 through 2009 3.5 Pontiac G6, Malibu, Saturn aura. The eighth digit in my VIN is N. this should be an LZ4 engine. If anyone knows for sure what is interchangeable please help me. Thank you

The interwebb wasn't very specific, however it seems like the only thing that would really need to be different would be the fuel system and computer. It may also have bigger injectors for the flex fuel application.

I think the fleets used flex fuel vehicles, which could explain the plentiful supply. Hopefully someone pops in that has fiddled accordingly.