Thoughts on how safe our trucks are

[MAC71]

I have a 71 C10 that I bought when I was 16 years old and still have it. It has been a supper reliable truck and has done everything that I have ever asked of it. I have always felt safe in it.
I bought a 69 C20 with a 396 about a year ago and did a bit of work to it and am thinking about giving it to my daughter who loves the truck and will be driving soon.
The truck is reliable and solid, but I have concerns about it safety. I have started doing a few safety modifications such as installing a seat with head rest and shoulder harness seat belts. On the 71 I installed a 31 gal blazer tank and will do the same on this 69 C20 to get the tank out of the cab.
My real concerns are is how will it really hold up in a traffic accident. My thoughts are that in the event of a "intown" accident because it sits up a bit and is heavy it would fair well but I am really worried abut what if she was in a accident on the highway. Its not designed to crush or absorbed a impact and where it does crush it would be crushing into the cab.
What are everyone's thoughts on this and does any one have any rear world experience on this? Here is a few photos of the C20.