The factory used a kind of trv thats no longer made. I used permatex ultra copper plus. No leaks either. The trick to useing any rtv is to get the surfaces clean. Getting all the factory sealant out of this area is what takes so much work. But once thats done its a simple job. BTW that front plate that covers the three gears sits above the top of the block so do not worry about how it fits. The top gear cover that aluminum fits up in the bottom of that cover.