Has anyone put these on there car and they could tell a differnce????

LT1 95 Z28.

 

Some have seen from 10-15 rwhp with 1.6's....1.7's are an option if you sticl with the stock cam...

NSA rockers with guideplates help with valve float where there is greater chance with SA rockers...

 

Yea, get some. NSA are stronger, also.

 

I've got a set of 1.6 ratio GMPP RR, Will these damage my heads, springs. I've got a stock cam.

 

no they won't damage your heads. You should get some better springs that will handle more lift though. The stock ones would be at there very limit with 1.6rr's. You should also put some new valve seals on there when your doing the job. If you do a search you will find tons of info on it.