How can you tell a difference by looking at them?

 

SAs have little protrusions on either side of the surface that contacts the tip of the valve stem. NSAs do not.

 

Besides the guide, whats the functional difference? If doing a rocker swap is there any reason not to get guides and be done with the SA?

David

 

AFAIK, the NSA's are safer for higher revving engines. The thought is that the tabs on the SA's could snap or break off. I've seen them, and they do look small. Anyway if you do go NSA, I've read that GM guideplates = correct and COMP = not correct. And you need hardened pushrods.

 

If you get NSA with GM guideplates and hardened pushrods - then you will not have anything to worry about for any application...

 

gotcha

 

So it's probably best to just always run NSA rockers?

 

That GM .vs Comp guide plate is crap. They both are a little off. But either is probably OK for 7K.

 

It depends, if the rockers are a stand-alone mod or you are just running a very mild cammed setup, then the SA rockers would be perfectly fine.