You never know what’s going to happen until you drop the engine in for the first time. The oil cooler is optional on the LT1 engine, but not on the LT4. Here you can see the interference fit with the Morrison Clip.
After removing the oil cooler you can see how it attaches and the path for the oil flow. The back side of the oil cooler has O-rings that seal against the pan.
I have recently read that there are block off plugs for these connections but I haven’t found them yet. I also think this a superior cooling solution for the LT4 which has a history of overheating oil issues during hard driving during track days. There have been a lot of negative posts on this issue lately and the new 2017 Z06 and 2017 ZL1 Camaro have many new added cooling features. I also think that by removing the oil cooler from the sump and relocating it in the front of the engine helps substantially with any potential overheating. It’s always much easier to add a larger cooler if needed.
If you look at any of the off-road buggy and Class 5 trucks, the oil coolers they run are substantial and many times are fan driven for additional capacity, they don’t use engine coolant to cool down the oil.