I wanted to overseed this year. I have about 70,000 sq ft of lawn.

My "All About Lawns" book says to mow it short, collecting the
clippings, and then scratch up the surface of the soil.

I have a mulching mower, no bagger.
If I mow with the mulcher, then run my dethatcher over it, can I
expect good contact between seed and soil?

I don't want to spend $200 on seed and not have it germinate.

Thanks!