Possible blown head gasket or worse

Obviously got too hot with no coolant.....

Hopefully the block is not warped also; it can happen. Hopefully not. At this point, use a composite gasket like Felpro, and be sure to torque per the manual and re-torque after a couple of short heat cycles. Watch for brown foamy stuff in the oil. Use green antifreeze like Prestone and resist the temptation to put in just water at first; with green A/F, you can spot any greenish content in the oil. Do your buddy a favor and just spend the few extra $$ for some anti-freeze even if you are in SoCal; these engines will rust up and scale up on the inside like any other and have cooling issues, and it does not sound like you buddy would bother to change it later. One gallon is all you need for those temps and you will get the anti-rust/anti-corrosion agents needed.

Flush the radiator before you fill up the engine with coolant.