Dont know about the 2.8 daihatsu engine, but I put the 2.5 n/a daihatsu engine in a series 3 lwb station wagon a few years back, the hardest bit was making a cable for accelrator, and making up a down pipe everything else was a piece of cake and I changed the daiahsu alternator for alucas one to do away with the external regulator on the daihatsu
used to sit happilly at 80 on the motorway and still have some power left,and did 28mpg aswell