Questions about 68 Yenko Camaros

[SS427]

I was recently discussing some 68 Yenko facts with a friend and we were not positive on a couple of things and were hoping some of the experts might be able to clear them up.

Which short block would have been more likely to be used in a post April 68 car, the 3935439 or the 3916321 427? Both were available after January and would likely depend on what GM had on their shelves so maybe there is no rhyme or reason to which could have been used.

Secondly, were all 11 of RS Yenko Camaros Matador Red or are there any other known colors that were delivered from Yenko in an RS? It seems like every RS I know of is Matador Red with a black vinyl top. Are there others?

Thanks for your help.
Rick