What is the call? Pulling guard comes around the end and the safety is on an outside blitz and sees the guard coming at him and since it is 165lbs vs 220lbs he folds on contact and takes out the legs of the pulling guard. All contact is below the waist. Legal or not legal? Federation rules.

Illegal. I'd imagine the ball had already left the free blocking zone, but that wouldn't matter anyway as I'd imagine the safety wasn't lined up in the FBZ either.

It all depends on where and when the block took place.
Blocking below the waist is permitted in the free-blocking zone when the following conditions are met:
a. All players involved in the blocking are on the line of scrimmage and in the zone at the snap.
b. The contact is in the zone.
The free-blocking zone is a rectangular area extending laterally 4 yards either side of the spot of the snap and 3 yards behind each line of scrimmage. The free-blocking zone disintegrates and the exception for a player to block below the waist is not to continue after the ball has left the zone.

And just to add to that...yes, obviously we would have to see it to make a call, but I would guess the safety was not on the LOS at the snap.

In fact, our chapter interpreter just asked our association to be particularly aware of this. Several schools in our area run a wing-T offense that features frequently pulling guards. Some defenders are apparently being coached to create a pile-up by cutting the lead blockers. I'm guessing this practice hasn't been flagged as often as it should have, and the offensive coaches have been complaining.