Cursed cast iron exhaust manifolds… apologies for the length. Trying to be complete.

The two that came with the 330 from an S24 (Adventurer) sitting in the S26 were both cracked with previous repairs failing. As someone else said in another thread about cast iron manifolds, “Forget about repairing them. They’re cooked.”

Casting numbers from the cracked manifolds have been all but obliterated by previous repairs — highlighted page attached.
Left side: 167XXXX - possibly a 1671128 off a ’56 Dodge or S27; 1676395 - may be original to the S26?; 1676932 or 1676372 both for a 57-58 Chrysler;
Right side:1675XXX - only manifold I can find with these #s is from a 57-58 Chrysler (1675932)

I also have two extra manifolds:
1637391: will not fit either side (not even close) — per the 55-58 parts book, it’s for Left side, 1956
1637390-1 or 1637380-1 (casting is hard to read): interesting in that it fits both sides — see pictures.
- However, cannot find 1637390-1 or 1637380-1 with or without the “-1” anywhere in book.
- If I had another one, modifications to the header pipe flanges could make it work on each side. I think.

Correct for the S26 is 1676395 x 2 but I’ve given up hope finding those. I think they would fit on the S24’s 330 because the heads from what I know, are interchangeable. But I’m not 100% on anything right now.

As I see it, the spectrum of possibilities are — in order of preference:
1. Get really lucky and procure 1676395 x 2 ($$$ but unlikely)
2. Find another 1637390-1 (or 1637380-1) and modify flanges ($$)
3. HHH block hugger headers -- https://www.hothemiheads.com/desoto/headers_related/headers_block_hu...
4. Full custom exhaust ($$$$$)

Questions:
Could someone please identify 1637390-1 (1637380-1)?
What is the prevailing wisdom? What would you do in this situation?

Thanks for your time to read and advice…

(Group-9-48-6_highlighted.jpg)

(1637390-1_LeftSide.jpg)

(1637390-1_RightSide.jpg)

Group-9-48-6_highlighted.jpg (240KB - 123 downloads)

1637390-1_LeftSide.jpg (239KB - 112 downloads)

1637390-1_RightSide.jpg (232KB - 120 downloads)