The 2.7l 3RZ Engine swap is much much much easier than many fear.
In fact, your friend can use his existing stock W56 and transfercase, as it is a direct bolt on to the 97's W59 bellhousing.
As for wiring, about 75% of the wires are self contained in the Engine > ECU harness, so all that is left to wire in would be the idiot gauges, ignition, alternator, starter, battery, and possibly rewire your headlights and blinkers.
As for the exhaust, I just routed mine down and below my bellhousing and placed my OBD-II cat right in the stock location as my factory cat, so everything up to the cat is compatible so he doesn't even have to change his exhaust system if he doesnt want to.
The factory 2-core radiator should be sufficient, but I would recommend using a 3-core rad. from either a 86-87' Turbo 22R-TE p/u or from a 3.0 3VZ 88-95 p/u.
If he has never done an engine swap that required wiring before, then he should expect to take about a month to get it finished.
To sample what you guys are getting into, check out my conversion:
http://board.marlincrawler.com/index.php?topic=4401.0Regards,
BigMike
