RPO X88 - Chevrolet Conversion

[MattDewalt]

My 99 Silverado has an RPO of X88 which stands for Chevrolet Conversion.  When I hear of coversion, I think of a van or truck that has been upfitted outside of the factory with aftermarket accessories.  When Chevrolet does this, what does it mean?  Or does it just mean that it is a GM truck converted by Chevrolet as opposed to GMC?

[BellevueSilvy]

I own a Southern Comfort Conversion truck but I haven't looked at my RPO's but being that Southern Comfort was the final assembly point for my truck I would presume that mine would have the chevy conversion RPO I will check and post again later with the answers.

[GnatGoSplat]

Yes, X88 = Chevrolet while Z88 = GMC.