Synthetic or non synthetic gear oil? whats everyone running?

[MTN4RNR]

i think im overthinking all this lol

You'll waste a lot of time and stress about it way more than you need to if you overthink it.

Follow OEM weight specs with a reputable oil company and you won't go wrong... You likely won't notice a difference synthetic vs dino as long as you follow the gear oil replacement interval.

 

[1000MPH]

Overthinking truck maintenance is a fine hobby.
I mentioned I use Delvac over on BITOG.
A friend of mine just did his Diffs with Chevron Delo Synth 75W-90 GL5 that is readily available at West coast Autozone stores for a great price.

https://www.autozone.com/greases-an...ynthetic-gear-oil-sae-75w-90-32-oz/443149_0_0