Thanks, good info.Nissan had issues with chain guide materials in the early VH45s but they fixed that in a couple years. The VQ series v6 are all chain drive.
The ISB, Powerstroke and Duramax engines are push rod engines. So even if there was a chain, it would be short and robust like the small block chevy timing chain. The old B-series are gear drive for sure, but I've never been inside the newer ISBs.