3443975 Radiator Info Request

It's becoming more and more of an odd duck....

Slant 6, original with 77k miles. Fender tag calls this out as well.

BUT...it has KH disc brakes and an 8 3/4" rearend under it. All seem to be original, no marks on nuts, no cleaned up grime, rear shoes srill have the Pentastar emboss on them, even undercoating on the hard lines at the frame rail.
I questioned it myself especially seeing the master cylinder that had two equal size reservoirs, but then read that the KH disc brakes used this style master cylinder.
Almost like it was deemed a 340 car and somehow got switched to a /6 car at the last minute. Seems weird...I was surprised to see the 340 radiator in it for sure.

Anyone have an idea of what it's worth? One on ebay is over $500 but I can't imagine that is reasonable.