a998 or a999

I'm trying to identify which automatic I have the numbers on the rail as best I can read is PK4202675X75035130 trying to figure if it's a 998 or 999 on the attached picture mine looks like this which i found at this link HELP

http://forums.moparmusclemagazine.com/70/8301171/general-mopar-discussion/904-trans/index.html

Like Tony said the only way to know for sure is to tear it apart.

BTW: All have 3 test ports like in the picture so that part of identification is null and void. Can't comment on the ribs.