Sorry for your loss.
Welcome to the forum.
LMC Truck is a good place to get interior and body parts for older Fords: Truck Parts and Truck Accessories
1999 was transition year for the 3.0l, it used longer head bolts and had smaller valves, the 1998 and earlier.
The head bolts for all were Torque-to-yield(TTY) style, i.e. tighten bolt to XX ft/lb then turn 90degrees, these hold better but CAN NOT be reused, once they are stretched they are stronger than regular bolts, but after being loosened they loose strength.
Read here about the 3.0l Vulcan engine and changes over the years: Ford Ranger II 3.0 liter Engines
3.0l Vulcan engine was also used in the Ford Taurus car, transverse mounted, these used a different head gasket than the Ranger 3.0l, has to do with coolant flow thru the head and block, so make sure you got Ranger 3.0l gasket set.
Ranger 3.0l Head gaskets also have a left and right(they will be labelled), the heads themselves do not, it has to do with coolant flow.