It is pretty mild. I think the takeaway from this build is the torque curve. Look at how low the rpm is at which it starts making 400 and how long it hangs on to 400 in the rpm range. Imagine you are pulling a 28' camper as the op is planning on doing. I think for a mild build it has the power right where you would want it.
I thought it was very impressive. Especially for a kid's first build. Even if it weren't, it's still a really strong combo. I'd be stout in a truck or A body. It's easy to get hung up on numbers. People sometimes forget what 400 foot pounds can do.