Rebuilt short blocks

MrSpeeddemon is right. I didn't realize they were so bad until recently I was helping a buddy rebuild his 454 and he ordered some valves off of E-bay cause they were cheap and when we got them they wouldn't fit the guides. The stems were about .005 too big. We talked to our local machinist and he said they were rebuilders valves that are used at el-cheepo corner rebuilder shops so they don't have to change out the guides when their worn. Cheaper that way you know since it's easier to swap valves than guides. He also told me of some of the things he has found similiar to what Mrspeeddemon described. The low price may look appealing but just remember "you gets what you pays for".