maybe 30 mins to take the old one and put the new one back in, and 20-30 mins to fix the odo and calibrate the speedo. u need to calibrate it after taking it apart for fixing the odo.
theres a how to on the tech library for that.
engine size doesnt matter. my truck is a 99 2.5 with tach, i just swapped clusters for the white gauges, and went with a 01 sport-trac 4.0 cluster, and works fine. only change is on the reset fuel light, its called check fuel cap on the 01+ trucks.
it doesnt matter if it comes from an auto or 4wd either. mine came from an auto 4wd.
my 99 cluster went to my bro's 00 3.0 that had no tach, it works fine on his truck also.
seems like from 95-97 to 98-03 a couple lights were relocated. so going 98-03 for the cluster will work fine(only exception is on the fuel reset light).
the look of my cluster