he's talking about the ignition coil that's mounted about 2" from the engine mount stud on the '89 and '90 engines
yes, under the truck, look at the rubber engine mount, the bracket that is attached to the bottom of it needs to come off, it's been 4 years since I had a 4x2 to look at so I don't know how many bolts hold it on, but I do know they are inside the engine crossmember sharing the space with the I beams, it gets trickier with traction beams instead of I beams as they are larger... somehow lift just that side of the engine (chain or strap around the intake manifold or something) and just take it apart.
as said, the passenger side LOOKS easier, but is harder, there's physically not enough room to get the new mount and bracket in place without swearing a lot. when I put the turbo engine in I ended up chopping off about 1/2" of the stud which would have made things easier... it made sliding the engine in easier dealing with the blower housing and turbo interfering