will 3.0 from a 93 ranger work in a 96 ranger

No. You cant' swap OBD1 and OBD2 engines.

Well, on an absolute basis, you COULD swap in almost anything that will physically fit, as long as you have deep pockets and time-but the swap you mentioned its not going to be a quick and easy job. Probably not something you'd want to tackle unless you have a lot of time, experience, and resources on hand. As F_O_R_ already mentioned, the engins are OBD1 (1993) and OBD2 (1996) So, swapping in the OBD1 for the OBD2 that's in there now means you'd necessarily ALSO need to transfer the electrical components that have ANYTHING to do with the engine management system. That includes all sensors, senders, at least PART of the wiring loom and the engine control computer. (I probably left some things out.) Also, when taking an unknown condition engine from a different vehicle you'd obviously have to check all the electrical parts to see if they are good, and replace any bad ones-which is an added expense over using a Ranger engine with OBD2-where you'd already have your old compatible parts on hand and get a bunch of duplicate parts with tthe engine being swapped in.