I always see these in peoples mod lists. What do they do? What does going to 1.6 rr's effect? Can I put them on my stock LT1?

 

Basically, the stock rockers are stamped steel, they look horrible and its just a metal flat piece pushing down on the valve. Roller rockers have a little rolling rod on the end that pivots as it moved up and down pressing on the valve. Also, the 1.6 rockers have a 1: 1.6 ratio that pushes the valve down more.

original lift/1.5=x/1.6

x=new lift...

 

The above adequately describes roller TIPPED rockers..
Full roller rockers also have a bearing at the fulcrum point...

 

Check out this link

http://cranecams.com/valvetrain.htm

It has some good pictures of different rockers, the top one is a typical aftermarket Roller Rocker for our car, the third one down is like our stock "Stamped Steel" rockers. Besides the additional lift provided from the higher ratio you also benefit from increased rigidity of the Aluminum Roller rocker Constuction which reduces the loss in lift due to flexing of the rocker. The rollers (both at the fulcrum and the tip) reduce frictional losses and sideload stresses on the valves. There can also be a reduction in weight over stamped steel which means that the valvetrain can react faster. Theese are just some of the reasons that roller rockers are superior to stamped steel.