Jim, you asked this same question
a little over a week ago! As I mentioned, this is not an LHD/RHD issue.
The pics you have posted show a 21A-9430 manifold from a 1942-48 car engine. The distance from the block face to the outlet face is 2 3/4in. Terry's pic he posted appears to be the correct truck manifold 78-9430, which is 2in from the block to outlet face. I note from your previous comments that you have a 221ci car engine, not the 239 that should be in a CMP.
There are frequently many of the correct 78-9430 manifolds that appear on e-bay, but none seem to be listed just at the moment. Keep watching and one should appear soon. I have a couple of spares here, but for the price of postage to the US, you could buy 5 in the US off E-bay!