I've run into a pretty serious problem with a 360/727 swap into my 5A. I had it rebuilt almost two years ago by someone who claimed to know what he was doing, but now looks full of it. The pan was full of rust (underside of valve body looks okay), and the selector lever cannot be physically moved into park. I don't mean it shifts to park and the car still moves, I mean you cannot actually shove the lever into park with all the linkages disconnected.

I ran some searches and couldn't really find any answers. If the pawl was snapped off, it would shift into park but still roll around, right? I know it's a really simple system, just an internal linkage, pawl, and slotted gear for it to engage.

Does anyone have any ideas?

It's possible that, when the park rod was installed into the tail, that it got shoved under the pawl instead of into position.