Oil pan back off, rear main cap off. The good news is, there is a seal. The rubber side seals didn't have the stakes in them, and had a very little bit of RTV where the cap seats in the block. The seal looks good. It looks like it was leaking on one side between the cap and the block. I'll get a seal kit so I can replace the side seals, and stake them like they're supposed to be, and use anaerobic sealer, like it's supposed to have. I'm surprised this was put together poorly, considering what the rest of the motor looks like. It sure sounds good. Or, at least it did when it was running.