I'm assuming you're wondering about cramming that 351 (assuming it's a Windsor, not a Cleveland?) into your Explorer?? Good luck!! Hope you like doing sheet metal work... I've heard that despite the 302 just barely fitting under the hood, the added height of the 351 makes it virtually impossible without some hood work. Then, fitting its longer trans (C4, I'm guessing?) and transfer case under it, you're looking at some extra length there... Trans cross members, driveshafts, fuel tank, et. al all pose an issue.
Electronics-wise, you're going to have all kinds of fits... the ABS probably won't be affected until you swap out the front and rear for solid axles (because the IFS isn't going to hold up to the power of a 351). The speedo is fed info from the ABS, so it shouldn't be much of an issue. The GEM, on the other hand, is going to have fits. Not knowing what it's connected to it's going to flash the 4wd lights (simple enough to remedy by pulling bulbs or letting them burn out), but the windows and door locks shouldn't have much of a problem.
The PATS system, on the other hand... That's probably not going to play nice with the carb'd motor and the lack of an EFI system. It's integrated into the instrument cluster... It may be possible to defeat it, but I don't personally know how. Some of the guys that have swapped in other setups could probably give you a better idea of how they made it happen.
Good luck, and let us know how it works out for you!!
