Welcome to TRS
Topaz did use the 3.0l Vulcan engine, '92-'94, in FWD setup, transverse(sideways) mounting
Distributor was used on all 3.0l Vulcan engines until 1995 when it was replaced with a Cam Synchro tower with Cam Position Sensor(CPS) on top.
Install/timing here:
http://www.therangerstation.com/tech_library/camshaft_position_sensor.shtml
In 1995 they also got a Crank Position(CKP) sensor, so you will need to change the timing chain cover, and crank pulley so that can be used on the older engine.
CKP is actually what replaced the distributor, it sets spark timing.
Timing chain cover has the mounting holes for the CKP sensor, and the pulley has the Tone Wheel the CKP sensor "reads".
Transverse mounted 3.0l engines used a different head gasket because coolant flow thru the engine was side to side, back of engine to front of engine.
In Rangers the coolant flow/hookup is all on the front of the engine so head gasket holes for coolant flow are different, sending coolant to back of engine then back to the front of the engine.
So it is recommended that you change the head gaskets when using a transverse 3.0l engine in a Ranger.
Many have not and have reported no overheating issues, but that doesn't mean that there are not hot spots in the engine causing long term damage.
So really up to you.
Be sure to put a sticker or something in the engine bay to remind you of what year the "new" 3.0l is, most parts are the same but not all
Changes over the years to 3.0l here:
http://www.therangerstation.com/tech_library/3_0-build.shtml