Yep looks like a Quigley conversion. There's some custom exhaust work going on there and I'm not certain it is fact a diesel. No badging on the outside and the fuel gauge doesn't specify diesel fuel as mine does, but the earlier models may not. I'm not sure. Anyone considering it would want to confirm it with a picture under the hood. If it is in fact a diesel, those power figures they've listed for the van are incorrect.
2015 Chevy Express 3500 Duramax
w/ Quigley 4x4 & Agile Fox shocks
Sold 2005 E350 Chateau
Quigley with Agile RIP, 6.0 PSD