Its almost same amount of work to drop 380 or 500. But I understand that availability might be a factor. I was lucky to score euro 500 when I had to change my engine.I did some reading about the various swaps people do. My preference would be to keep it Mercedes and somewhat straightforward, just so it gets done in a timely manner. I think as far as fun goes the 500 engine would be the way to go, but my wife is fine with it just being a cruiser. There doesn't seem to be an overabundance of older Mercedes donor cars near where I live. We're going to go check out a 380sec with a bad tranny, but good running engine and see if we can make a deal on that. It's a little bit of a drive but hopefully worth it.