So by all means id say go with stainless rockers and never think about them again. The comp cams pro magnums are steel and on the tip where it matters are actually lighter than aluminum.
Rocker Arms
Stainless steel roller rockers vs aluminum. I have some questions concerning the use of aluminum roller rockers on a street engine with a stock type camshaft and valvetrain. Steel roller rockers and rocker ratio in daily driven high mileage fleet vehicles. Steel rockers flex less than aluminum ones which is part of the fatigue life issue. It depends on the rocker. This week were talking about aluminum vs. The company offers four lines of stud mount rocker arms the sportsman series pro series aluminum pro series steel and performance quotient platinum series steel rocker arms.
The sportsman series rockers are constructed from 4340 steel and use a roller tip to reduce friction and minimize scrubbing the valve top while also working to free. The reason stainless rockers last so much longer than aluminum rockers is that steels fatigue life is far longer than aluminums. With those cam specs aluminum will be fine. Steel typicaly is much better for most applications. Comps pro magnum roller rockers are designed to be an effective middle ground between inexpensive aluminum rockers and extremely strong and reliable but more costly stainless steel rockers. They are heavier in full weight but lighter in the way there designed lighter on the valvetrain.
Im in the middle of buy some roller rockers and i have always thought that the aluminum roller rockers where the best because they are the lightest but i have read that the steel roller rockers are the best option. Stainless steel rockers arms vs aluminum rocker arms stainless steel rockers are a bit heavier but stronger aluminum rockers are a bit lighter and a bit weaker when stressed with 800 pounds spring pressure open. Solid roller spring rates combined with rpm require a good steel roller rocker. In an engine application aluminums lifespan is significantly shorter than steel or stainless steel due to the fact that it fatigues faster. In general steel will be stronger but its strength you probably dont need. Steel body rockers are stronger than aluminum rockers.
Aluminum is used in alot of applications because of weight requirements but in the case of a rocker arm with correct design the weight where it matters can actual be less with a steel rocker due to steels strenght.