Those boxes not only are a quicker ratio but also are "heavy road feel". The box will feel nothing like the stock box. Does it feel different than with the engine not running? If it feels the same with no engine, then something is definitely wrong. However if it feels different, then everything should be fine.
20 years ago when I put my first Monte Carlo SS box on, I left my friends shop and was going for a one finger right turn(beer in the other hand) and almost hit the curb in the oncoming lane. The feel is similar to new cars . It's still power steering but nothing like the one finger factory set up..timo22