318 exhaust manifolds

I am about ready to take the polished TTI headers off of the Barracuda, and install a set of nice stock manifolds that I have put together.

Part numbers are 2951123 and 2843953. They show to be for a 68/9 Dart, 318.

I wonder why the listing shows a different part number on the Barracuda for the left side? Has anyone ever run across this? TTI says they have never heard of the 2951123.

318 1968-69 Barracuda / Right 2843953
318 1968-69 Barracuda / Left 2475719
318 1968-69 Dart / Right 2843953
318 1968-69 Dart / Left 2951123


TTI says they have never heard of the 2951123. The rest of the system is TTI, so I wanted to order a set of head pipes from them, but cringe at paying the price.