For whatever reason Warn uses the outer groove that the old auto hubs used. Aisin and Superwinch use the larger inner groove that the drive plates use.
When I had stock rims and put my superwinchs on I used a 3.5" hole saw to cut out the center cap. Looked much better then without it.
$80 for Aisins? Mine were $30 a pair at the local pull n pay here.