It's also incredibly easy to have the short locating dowel slip out of its hole in the thrust washer; if your washer(s) have a series of small dents in the bronze surface near the pin hole, they came from the washer being mis-registered during assembly.
Regarding the locating dowel bosswrench mentions, these are the thrust washers I removed during my rebuild. Obviously, the gorilla previously owned/worked on my Pantera only got one installed correctly. Anyway, the dowels that caused the damage were worn down to nubs and had to be replaced. So, I was VERY careful to locate the dowels in the thrust washer during assembly--grease and a big clamp for sure.