Ball Joints and Axle changes

[Batphreak]

I need to put Ball joints in my truck. I started by looking at Rockauto, and someone with an older truck told me about the Spicer units for a very reasonable price. Turns out those are only listed for '97 and older trucks, the Spicer units aren't listed for my truck. I e-mailed Rockauto about it, they say Spicer doesn't rate their units for service on '98 trucks. So, all of you that have worked on a lot of these trucks, I want to know what you think.

The Moog ball joints (I know they are superior, but 'spensive compared to the Spcier ones) are the same part number for '94- at least '98 trucks: K80026

I decided to check other sources, Advance has TRW ball joints for my truck and older ones same part nubmer: 10339HD

For whatever reason the Spicer joints #: 5001048B are only listed for '97 and older trucks.

I'm thinking about just trying the Spicer ones, but I don't know enough about year-year changes. Does anyone know if there really is a difference betweeen the '97 and my '98? If so, why do Moog and TRW list the same joints for both years? (the part numbers I listed are for upper joints, the same situation occurs for lower joints).