intake valve seals??

[durk]

Hi,

I bought a flathead engine for my 35 Ford. According to the previous owner, the engine is perfect.

The engine is running. But smokes when I let go of the gas. Idle is good and when I accelerate it is also good but when I let go of the throttle it smokes a little bit.

In a modern engine I would say, 100% the valve seal.
But in flathead I am not sure. hard for oil to run uphill