I am in need of replacing my factory oem ball joints that have 90k on them. The two I am looking at are either Synergy or Alloy USA. Is there much of a difference in the two other than the price. It looks like Amazon will sell the Alloy USA for $100 less? I really don't want to cheap out and get what I pay for, but I also don't have the coin to buy Dynatrac ball joints (wish I did). any thought?