They will look like fingers that hold the pushrod from moving side to side. If you have them, you have hardened pushrods already. If not you need the whole deal.

If you have allum heads, you should have screwed in studs, as you were told above. If so, you can buy guide plates if you dont already have them and get roller rockers installed very easily. For long term use, if cost is not a factor, I like the Crane Gold Race rocker. Here is why, it restricts oil out of the pushrod, but at the same time it has an orifice that directs the spray of oil from the pushrod pocket directly at the roller fulcrum and the roller tip. It is a roller propriety oiling system for the heads. Once you go to a roller fulcrum and roller tip, your oil requirements go down. You will be producing less heat, and therefor need less oil to cool the springs and other parts. This makes more of your engines oil volume available for your rods and mains. Its a good thing. Crane also makes a street use roller lifter that is an economical allum roller, but it does not have the orrifice/spray control that the pro-race has.