I use Valvoline High Performance Gear Oil 80W90 on my 02 c1500 and my 95 Silverado. Both have Detroit Truetrac's though which calls for dino-based oil, not synthetic. Have had absolutely no issues with either using the dino-base oil. Probably use the same Valvoline stuff when I swap in the 14b ff with a G80 too.
Valvoline™ High Performance Gear Oil is a high quality lubricant to keep your vehicle running in great condition and avoid loss of corrosion protection. Find this and other Valvoline brand products you need.
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