I have a 94 ranger with a 4.0 and auto tranny, the engine is bad but the truck only has 80,000 miles so it is wirth replacing the engine. I have found a 95 engine and a neighbor has a wrecked 2002 truck , both 4.0 engines. How new an engine can i swap it out with and how much trouble will i run into? Any help and info very much appreciated.