I had a small block chevy that would smoke like a pig if I hit the brakes hard but would not smoke on start up acceleration or deceleation. I did a compression test and was perfect all the way across hot and cold I did a leakdown test and that was perfect also yet I still had gray smoke when I hit the brakes hard. I checked it with the brake booster disconnected thinking it was bad and the engine was sucking in brake fluid making the smoke but I still had smoke when I hit the brakes hard. I finally pulled the heads off and found the #1 cyl wrist pin was coming out of the piston and had a 1" wide 1/8 " deep trench dug in the side of the cyl. The wrist pin must have been sealing in the trench giving me a good compression test but when I hit the brakes hard the oil would slosh to the front of the motor getting in the trench and making the smoke