Freshly rebuilt: smokes

[Oddmodman]

I bought a 740 GLE a couple years ago, the PO had just rebuilt the motor, and was selling it because it smoked. I don't know if it was white or black smoke, and it was long enough ago that I don't remember, but according to a neighbor who knows something about them, he said it was due to either injectors or the IP. I'm inclined towards the IP being incorrectly timed personally, but that's just my favorite theory, I don't actually have many details about it. Wondering what you all think.

Also, completely separate, I am very interested in putting this engine in my '65 P1800. Anyone ever done that? (Also putting this last statement/question in a different thread).