Rocker Arms SBC with "O" on the end

[opelitis1]

Small block rocker arms with the "O" on them... I have heard that these are better than the more common "V" type...   Why???  I have maybe 15 of these O arms and cannot see any difference..
Maybe it is my vision, eh???   Ted

[firstgenaddict]

The slot in an O arm is supposed to be longer for the high lift cams.

[PACE&Z2869]

I believe the "o" stamped rockers are a long slot rocker for higher performance engines. The newer rockers are also long slot as GM probably wanted to standardize a p/n. As opposed to the older low performance rocker arm which wasn't a long slot. Higher lift camshafts required a long slot rocker.

[opelitis1]

How old are these "O" Rocker arms and were they in fact specific to a certain engine or car model???  I've had them for 10 years and the person I bought them from must've had them for maybe another 10 years B 4 me....  In the olden golden days, what did we in fact consider a "high lift" cam?  Anything over .450 and were they used in "solid lifter" cams only??? 

[JohnZ]

The "o" rockers are also heat-treated differently for durability; the lash clearance on solid-lifter engines is much harder on the rockers than the constant zero-clearance of hydraulic lifters.

[opelitis1]

Good info Mr JohnZ... Had these for sooo many years and basically never knew what I had or why and what they were used on....   Merci!!!  Ted