Chevrolet Repair: Rear end gasket and oil, posi traction, posi unit

Question
Hello friend, I have a 1994 Chevy c1500 Mark 3 edition pick up truck. I want to change the oil and gasket in the rear end. I was looking for the model number for the gasket I need to order, and also the oil I need to use? It's a 2wd, was a V6, I put a 350 in it, but the rear end is still the same, for now. I think that is it, I really appreciate all the help, thank you so much!!!!

Answer
HI RANDY, THIS IS PROBABLY NOT A POSI TRACTION REAR AXLE BEING A V6.  REAR DIFF COVERS FOR MANY YEARS DO NOT HAVE GASKETS ANY MORE.. [CLEAN] THE PAN AND REAR AXLE HOUSING SURFACE OFF OF THE OLD THE GASKET MATERIAL AND USE A 1/8 "BEAD OF SILICONE SEALER ON THE COVER,PUT IT ON THE AXLE HOUSING AND TIGHTEN IT UP AND YOUR DONE. NOW AS FAR AS THE GEAR OIL GOES I WOULD GUESS AND SAY REGULAR 80W-90 WT GEAR OIL. HOWEVER ONCE THE COVER IS OFF YOU WILL BE ABLE TO SEE IF THIS HAS A POSI UNIT OR NOT. IF POSI YOU WILL NEED TO USE SPECIAL POSI LUBE ONLY SO THE CLUTCHES DO NOT SICK GOING AROUND CORNERS. IF YOU ARE NOT FAMILIAR WITH WHAT THESE REAR DIFF'S LOOK LIKE I COULD EXPLAIN BUT IT MAY CONFUSE YOU. MY ADVISE WOULD BE TO CALL YOUR LOCAL CHEVY DEALER AND GIVE THEM THE LAST 8 OF THE VEH ID #'S  AND THEY WILL BE ABLE TO TELL YOU WHAT REAR DIFF IT HAS AND WHAT OIL TO USE..YOUR OWNERS MANUAL WILL ALSO HAVE THIS INFO. I HOPE THIS HELPS YOU,IF YOU NEED MORE INFO PLEASE GET BACK TO ME. WOULD YOU MIND RATING MY ANSWER WHEN YOU LEAVE THIS SITE,GOOD OR BAD. THANK YOU,,, TOM..