... should be stamped into the steel. Also, there might be a set
just forward of the drivers side #3 body mount (which is
impossible to see without lifting the body). Some lacquer thinner
and Qtips might clean the top of the frame rail enough to make
them out. I have also read about using an inspection mirror to
see them better ... good luck.
On the frame kickup - next to the top of the rear tire - is the fuel
vapor line. Follow it back and up to the top of the tank. Rear brake
lines are at/along the lower differential (called rear) crossmember.