Accurate Fitting 273 Exhaust Manifold Gaskets?

Yeah, those are for mid '70s and up LAs that have smog pumps and air injection ports below the exhaust.
You can try something like these- just prepare for sticker shock wherever you get them...
Mopar 273-318 Exhaust Manifold Heat Shield Set - P29451285 NOS CHRYSLER for sale online | eBay