what type of fluid to use in a 92 Chevy pickup manual transmission

According to Mitchell Repair there were two types of manual transmission used that year. Here is the listing for fluid recommendations. Please contact Rick's Automotive if we can be of assistance. 417-887-2225. Trans Mfr CD 5LM60/MG5 API - GL-5, SAE 80W-90 Add 4 oz. of Friction Modifier (4318060) or equivalent on Sure-Grip differentials. 2.20 QTS. (2.1 L) S Trans Mfr CD NV4500/MT8 GM Synthetic Lubricant or API - GL-4 Castrol Syntorq Add 4 oz. of Friction Modifier (4318060) or equivalent on Sure-Grip differentials. 4.00 QTS. (3.8 L)