Why does my 1996 Lexus ls400 smoke every time you turn it on?

I have a 93 with the same problem. It has 126k miles which should be nothing on a Lexus. I am going down the path of valve guide seals with mine. I'm pretty sure I'm right, but I will consult with a more experienced mechanic before I proceed with repairs.

What happens is that the oil sits in the valve train area after the vehicle is turned off. It then leaks past the bad seals into the combustion chambers when the is not running. When you start it, the excess oil combusts causing smoke. Once this oil is burned off, the car stops smoking. That's because the oil is circulating freely while the engine is running.

This will probably be an expensive repair at the dealership. I plan to fix mine myself.