The block would be a C4 block number. It is a specific block for my 64 cobra.
I would be very interested in the block as it is close in time frame and I believe I have a another set of hipo main caps. It is not a problem to sleeve them back to standard.
I get the impression he's looking for a very specific block. BUT just in case, I have HiPo block serial # 3179. Casting number C4OE-6016-C. Casting date "3L21" (November 21, 1963). Assembly date "3M4" December 4, 1963. Unfortunately, it's .030 over standard and no longer has the HiPo main caps. Let me know if interested. I haven't had the heart to send it to the scrap heap yet.
