You may want to check out my link below for OCPJP7. It shows what resources I used for the upgrade prep.
Since you are v1.4 certified, and there are a quite new features in v5,v6 and ultimately v7, such as generics and new API in the collections (v5/6), and java 7 exam topics (
jdbc, nio2, localization, concurrency)
Anyway you may want to look at my link below for OCPJP7 which I passed the upgrade last month.