Safe roll angle

The reason it is not published is they are never the same. Ground conditions, speed, load, air pressure in tires and especially angle of steering wheel. It can vary several degrees depending on the variables listed. For rule of thumb, if you get to 30 you have bigger balls than most everybody.
With that said, I have rolled a truck on a side hill. Hit a slick spot, slid down a bit, wheels caught and slowly rolled up on the side. The truck I rolled was not a 3rd gen, it was a 78 Chevy Blazer.

 

I did above 40degree slowly