Looking for 7.20" push rods...

It appears that shaft shims would move the contact patch towards the exhaust side of the head. But it will also affect how it moves around and in which direction. But without doing it myself, I can't say at the moment what the results will be.

But there is a thread here on the subject:

http://www.forabodiesonly.com/mopar/showthread.php?t=99993