65 Dart gt convert on ebay?

This car is said to have the original slant six thats numbers matching, but the plate under the hood says that originally had the 273 4brl mill instead!! Look for yourself in the pics, it has the 31 code instead of 21..

http://cgi.ebay.com/ebaymotors/Dodg...temZ140502848207QQptZUSQ5fCarsQ5fTrucks#v4-41

Am I crazy?