I haven't messed with ujoints before, would be willing to learn. My only concern is I don't have a press and I have seen a few things saying the cv end is difficult to deal with and the socket/hammer method really shouldn't be used.
As for the 513's, my driveshaft guy says he won't touch anything aftermarket for Toyota joints. He will only put Toyota joints in there. I also feel like I've read reports of 513's blowing up. Is that something to be concerned about?