aluminum heads
 

If a yenko was ordered with aluminum heads, were the heads painted, or left untouched to match the intake?

Re: aluminum heads
 

If you are referring to Yenko Camaros and Chevelles ordered through the COPO process (1969) or Yenko converted 427 cars (1967-1968) I do not believe there are any documented examples of L89 optioned cars so your question is based on cars that don't exist. I wait to stand corrected on that, of course...

Now, Yenko probably put in a few L88 engines (aluminum heads) into customers' cars at their request, but those crate engines would have bare aluminum heads.

However, L89 optioned Chevrolets did not have the heads painted; as a general rule they were bare aluminum in appearance.