Engine Oil & Rear End Fluid

[95strokerPSU]

Just wondering what kind of engine oil and rear fluid you guys are using. This upcoming weekend I'm putting in my 331 stroker in and I just want to know what I should in it. I heard synthetic isn't good for new motors but I'm no expert! I'm also putting a rear support cover on to help hold the rear together so I need to change the fluid...what should I use?

 

[Venom351R]

Im running Mobil 1 but my motor is not new either. I just use plain old NAPA rear end gear fluild. Synth fluids in an Eaton or Auburn will chew them apart. My friend's Eaton was trashed after running Synth fluid in the rear end for awahile. As long as the oil level is full then just reg rear end oil is fine.