I use aftermarket a 10" and a 12" toghether on an Stock EA81 radiator cooling the EJ22 in my wheeler.
If you buy 2 good quality aftermarket fans, it will work fine. $40-65 each...........from Napa, not $10 ebay fans.
But DO NOT use the stupid pull through mounting plastic tabs. These put the fan right against the radiator and vibrations will cause the fan to rub intot he soft brass radiator and make a hole. Or they will break, because they are cheap plastic tabs.
take time to build a metal frame that bolts into the OE mounting holes. 1/4" bolt heads slip nicely into the mounting slots. Those bolts can then either be welded or threaded into a piece of angle iron top and bottom. then that angle bolted to the radiator face's OE holes.