Re: 05 Mustang 4.0 in my 02 Explorer?
VIN "E" generally means that it's the same type of engine; 4.0L V6 in both cases. The only thing I can think of on why it wouldn't work is if the engine mounts line up or not. If they do, be sure to take the mustang PCM and wiring harness as well so you don't have any problems with emissions or drive-ability. If you can find out if the engine mounts are the same, then you'll know. If I were you I'd find a similar engine from an Explorer, not to only play things safe, but then you can reuse the current PCM and wiring harness and save additional $. If you plan on keeping the Explorer for several years I'd suggest on contacting Jasper Engines if you live in the USA. They have rebuilt warranted blocks available and can even install for a moderate fee. It'll take a bit more work and cost a bit more, but at least you know it'll be 1000% more reliable than another used hand me down engine.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!