Don't know how much this helps
but Discoveries are bulit like Tanks
but the Transmission and the T-case are bombproof very tough and quite low geared for a stock vehicle. The engines are good don't let them overheat.
the 95 came with a 3.9 V8 ( distributor) and 96-99 came with 4.0 V8 (coilpack) electronic management system.
neither will win any speed contest but overall are quite realiable if maintain very well.