I'm getting ready to change the rear differential gasket and oil in my '51 3100, but when I checked at NAPA and classic parts, both are telling me there are two different gaskets available. Both 10 bolt, both the correct diameter. Does anybody know what the difference is between the two, and does it matter which you use? Does one not fit the other's application? Is one cork and the other the other silicone? I'm not taking it off till I hear from someone. NAPA will have one of them Monday (said the other might take a week). Thanks.
