I think I have posted this before, but here it is for those who missed it. Follow this link to download a 4 part series on rebuilding a Plymouth flathead six. It is written by Curt McConnell and was published in Auto Restorer magazine.
http://esnips.com/web/PlymouthFlatheadSixsBusinessFiles
Good article. He also went to a lot of effort to do a very nice paint job on the engine and the accessories.
Except that 1937 is, I think, the first year for the block to be silver and he painted it black. I hope for his sake that I am wrong.
There has been a lot of discussion of late on early Plymouth engine colors and a lot of research on the subject has been undertaken by various club members and technical advisors. A major article on the subject will appear shortly in the Plymouth Bulletin when the article is completed. At the present time I won't say which color is correct or incorrect....
Engine colours.
I bought an unmolested 37 Plymouth back in the sixties. It had a black engine block and aluminum painted head.
The PJ I had before that was the same and it was all original too with no evidence that either block had been repainted. dp
My P 10s had aluminum painted heads but I cannot be certain about the blocks. US built 41 Chryslers had red engines.
Every postwar engine I have seen in its original condition was all aluminum.