I built the Revell Charger Police Car Edition a few years ago. It was all I could find at the time. The engine is actually the 5.7 Hemi, but with the engine cover it's hard to tell. I think the 6.1 in fact doesn't use an engine cover and the top of the induction system and the ignition are exposed. Most of these systems are in this kit in a basic form but with a little detailing you could make a very convincing 6.1 liter.