Here (attached) are some 1993 (same generation of pre-Tacoma Toyota pickup; aka 'PreTaco') FSM documents on basic lubrication / maintenance.
I recommend your buddy download the 1993 FSM documentation here for future reference:
(about 32 Mb)
The 3.0L 3VZ V6 engine does not get a lot of love. The three main gripes were (a) its relative lack of low-end power, (b) its notorious reputation for blowing head gaskets, and (c) the very low amount of aftermarket support.
I got almost 150K-miles out of my 1993 3VZ with no more hassles than a new head gasket (not yet blown; under warranty) and a new water pump (circa 90 K-miles). IMHO the 3VZ is the least desirable Toyota pickup engine of the last 30 years, but it's not the total disaster its reputation might suggest.
IMHO the best source for general information and discussion on these pre-Tacoma pickups is ToyotaMinis.com.