I ran a 850 mighty demon on a stone stock super high mileage 81 302 engine, I had to run VR1 20-50 in it to keep the bearings from knocking, and only had 20 psi max pressure at wot. It worked fine, I even sprayed 5 bottles through it at 175hp shot. It ran stronger on the motor after the first few nitrous runs. Who would have thought.