The 3 inch garage door sheaves I ordered are a perfect replacement for the ones installed since 1996. The ones I replaced had bad bearings due to the use of 5/16 vice the required 3/8 attaching bolts and 14 years of service. The price was better than anywhere else and I received them lickity split. I'll most definitely shop Preferred Doors again.
I purchased 12 of the 13 Ball Nylon Garage Door Rollers that were very well priced. They appear to be good quality. It is the sealed type bearings. Only time will tell if the nylon will stand up to use I put them through. At the price I purchased them I got two extra just in case. They are already much quieter than the metal rollers. The older ones had been on their for at least 15 years and if these last that long, the next owner can replace them.