OK,guys, first of all, thank you all for your input. If I interpret the postings correctly, the 819 head I had on my truck was not original to the 1946 model year, nor were domed pistons. Furthermore, the pics I sent of the domed pistons which are in my motor are not OEM. Okay, I get that part, however "gmc-is-me" responded that my pistons were custom for the 819 head, while "crenwelge" replied the 819 head uses flat pistons. I'm totally confused. I had domed pistons in a 819 head, on a 228 ci engine, which until recently ran fine.
As I go forward, do I search out 477 or 412 heads to accommodate the existing domed pistons, or do I search out flat topped pistons which are compatible with a 819 head ?
