Whenever i go up a hill and get near the top my blazer starts shaking and sputtering. It goes away after i rev it up a bit. Any thoughts on what to check?

Any check engine lights or blinking check engfine lights?
Any stored codes?
If so post back code no.

First thing I would check tune up end and confirm good fuel pressure.

Good Ac delco plugs and good fuel and air filter.

What engine and transmission and mileage?
When was the last good tune up?