I am wondering if anyone has found a site or company that sells headers (full or short) for a 1964 ninety-eight?

 

HAHAHAHAHA...

Good one. The best you will do is a set of header flanges that you can use to custom build headers to fit:

http://www.headersbyed.com/__oldsmobile.htm



You can buy lakester headers for a first gen Olds, but those won't do you any good in a Ninety Eight:



http://www.lakeheaders.com/oldsmobile_headers.html