Nothing earth shattering. I've heard estimates in the 5-15hp range by itself. I take those with a grain of salt.
But with a little cam, headers and a tune in hoping to pick up some. I would be tickled pink to get 250hp out of this 305 with the TBI intact. I might have to go to the LB9 heads but I've heard with a little work these LO3 heads will support 375-400hp. Not that I'm looking for those numbers from this package though.
I grabbed it because of how good a deal it was, I want to get gears and do some transmission work before I dig into the engine.