Your tank will need to meet the minimum requirements to even dream of a raid. Fresh lvl 80 blue/green quest gear??? I doubt it.. It's hard to down some heroic bosses if your tank is in that gear.

Example, I just dinged 80 on my paladin and 4th mage, I walked into NORMAL ToC 5 man with him in all the +defense quest blues I could find with a naxx 10 geared healer and could not down the first boss due to lack of tank gear.