beats me, IIRC it came from a dead nissan efan, made some holes in it and coupled to the water pump with a custom flange, pulls as much air as the old mech one but weights lots less, no more overheating problems, finally... if i only put a shroud on it it´ll be more efficient but like i said it has not overheated as it is, and i live in a place where 40 degrees in the shade is considered "normal"...
a few weeks ago i had to tow my friends WJ (dead ECU) and after 10 miles or so it began to over heat, first time with the plastic fan, i let it cool and kept going for another 10 miles with no problems... may add an efan for such situations...
the ones that bolt on won't fit, the ones that fit will not bolt and the ones that fit and bolt will rotate backwards so if you find it, please share
a design leftover from the old 258?