Keith you could certainly give it a try. I would fill in with soil then tamp it down good so it will stay put, then I would leave it set until after a rain to see if the fill settled and would need more soil. When it looks like you have enough fill in place put down your grass seed and put a little soil on top just to hold the seed in place. My husband did it this way after we put in a sidewalk it worked well in our climate. We did make sure it got extra water the first summer. I would also put up some stakes and twine to keep anyone from parking there until the grass is established. One more thought since there is sod there you could always get some extra sod and put that down after it is filled in with soil, it would get established much faster than grass seed.
