I have a set of rocker arms that I think are from a 57 312 and how can I tell if they are the good ones,was there a 4 bbl 292 option in 57 as I also have the 4 bbl from that motor.  A friends dad scrapped a 57 years ago and these are the left over parts from it and if they are the good rockers I will use them on my 292 build.

Butchering up everything I can get my hands on in Dayton Ohio