Just to make sure, will the stock rockers work okay on PP S2 heads, either 5.3 or 5.7? From what I have searched, it seems as if they will. Is there any real advantages to upgarde to YT's? The car has less than 27,000 on it, so they should be in good shape I would hope.

yes stock rockers are fine, on either head. advantage of new rockers are they are true roller rockers and you'll have a quieter (sp) vavle train and there stronger.

HP wise I do not think there is a huge advantage or at least I have never seen any posts bragging about them. I think most people do it for peace of mind know that the upgraded rockers will not grenade before a stock one (at least they are hoping that is true). I know PP had problems a while back about their springs rubbing stock rockers. At the time you could buy YT or grind your stock ones a bit either way would have worked except one was obviously a lot cheaper. I know PP has new springs now so I think clearance issues are in the past. FWIW from what I have read stockers are little easier to setup, maybe someone can chime in about this point.

Thanks. I had read about the problem you touched on, thus the post. I started reading about having to shim the aftermarket rockers. Sounded a little beyond what I was wanting to do since I was thinking of installing them myself for the first time.

After market rocker arms are advised, but not always neccasary. It really depends what springs are on the heads.

I personally have never been a big fan of grinding the factory rockers either. It isn't a part that has a lot of structural integrity to start with.

Ok here's the deal. I had Stage 2 5.3 Heads from PP. I had the old style with the bad springs on it which were really big at the time. I grinded my factory rockers to clearance them to work, I barely took off anything just very minimal. Well I ended up snapping 2 of the rockers!! So DON'T grind them. I had to overnight a set of Yella Terra's because I was 2 hours from home. I am now running the Stage III LS6 heads. I have the Yella Terra's and ran them on the heads and am currently sitting with factory rockers on the heads. My plan is to dyno the car with both sets of rockers to see if there is any difference. SOTP I think I lost a little HP going from the YT's to the stockers however I'm not positive. The reason I changed was because I wanted to see if what I have read in theory is true. The yella terra's may be lighter however more weight is over the valve with them which in turn promots valvetrain float. So I'm not sure as to the results yet but will keep you informed.

-Sly