Exhaust has white smoke coming out and I dont know why...

[Dave W]

The first 2 options on the list you would see black smoke from a rich mixture. The 3rd, I assume you mean that the new piston rings are not sealing in the newly honed rebuild cylinder wall, and in that case, you would see a bluish tint smoke from the oil. The 4th you will see the white smoke from the coolant. As already suggested, if really want to find the cause, you need to pull the head. You can always try stop leak product, that might fix it. Dave W