Maintenancewise, what would be the better choice? I don’t know the differences between the two regarding timing chains etc. between the V8 and V6. I want something that will last and be minimal fuss. Thanks for your input!

The GS350 is both a simpler car, and a newer car. When buying used how the car was maintained and driven is more important. My initial answer is if all things were equal, and they almost never are.