Romar,
In my search for this information I have found there is a great deal of disagreement, though everyone seems to have their own definite opinion of what is correct. The Walter P. Chrysler club publishes a document which lists the engines as black with a silver head (if silverdome) or red head (if red head). However they also list exceptions to this color scheme, in particular they list a SilverGreen that was used on the Imperials as having been used on 'some' chrysler 4's and 6's through the early 30's. I have 3 blocks for a 1930 Chrysler 77, one of them appears to be all original and is silver green. Another one is painted silver green, but this is over red which is over grey. The third one is black, over red, over silver green.
I have been told that the AACA and WPC accept the black blocks as original. In the case of the 1930 Chrysler 77, I have seen a 50/50 mix, however all of the engines that were reportedly original were Silver Green, and all of the engines reportedly rebuilt or restored were black or red. I am no expert, I've been trying to get a definitive answer to this question for over a year.
While it would be simpler to go with the flow and paint my block black, it appears to have originally been silver-green. My personal preference based on this is to paint it back to the silver-green. Unfortunately I have yet to find anyone who has the codes or the paint for the silver-green. I may eventually be forced to live with the black due to my inability to get the proper engine enamel color. If you know where to find the silver-green I'd greatly appreciate the information.
Well I doubt I have answered your question but put simply as I understand it:
Black is universally accepted but may or may not be original.
Silver-Green may or may not be original for a given engine and causes discontent with many self appointed 'authorities'.
For me, I want my car as original as possible to what it originally was, I'm less concerned about the AACA/WPC/VMCCA or any other organization and more concerned with the preservation of the vehicle as it was originally produced.
My two cents (and then some) worth. Hope I've at least helped out some, if not confused a great deal.
Rich
PS: The wpc paint list can be found at:
WPC Engine Color Chart