what exactly are u tryin to accomplish with this? im just wonderin..then i can answer the question better..
First off, you'd have to convert to the 4wd spindles. There is a massive size difference because of the axle shaft that runs through the spindles. Then, if you were to covert to the 4wd spindles (or even the 2wd prerunner spindles), you would have to modify either the height of the spindles or the location of the lower control arm. Either way, it would be a huge undertaking for a 2wd six lug conversion. You'd be better off running wheel adapters up front. They'd add a bit of width, but be much cheaper.
