If your talking about the original ductile iron Mopar adjustable rocker arms found on the 300letter car motors and M.W. motors they do vary from 1.48 up to 1.53 ratio
![shruggy shruggy](/ubbthreads/images/graemlins/custom/shruggy.gif)
if your talking about the early Isky ductile iron and other brand ductile iron adjustable they vary also
![shruggy shruggy](/ubbthreads/images/graemlins/custom/shruggy.gif)
RAS use to bush and correct the ratio, even increase them up to 1.62 or so, but if your going to buy a use set and have them fixed why not buy a good new better set to start with like Comp Cams stainless bushed or some good aluminum roller rockers like T&D or Harland Sharp
![work work](/ubbthreads/images/graemlins/custom/work.gif)