When you torque things down it can cause the gasket to tear in areas that have holes or where bolts go through. This can of course cause leaks. Silicone can also get squeezed out and become debri in your oil and oil passages. Bad for the oil pump. When I took apart my old NA motor I was able to pull strings of silicone out of the oil passenges between the heads and block. RTV was used on the oil pan.