Rocker Arm Identification

Here is a quick break down on how to Identify a T&D rocker arm

The fastest way to I.D. our rocker arm is the shaft Diameter and adjuster screw size. The majority of our rocker arm’s use a 5/8 or .625 diameter with very few exceptions. Also the majority of our rocker’s use a 7/16-20. However we do use a 3/8-24 in our steel rocker and in rocker arms that are tight in the valve cover area like the LS platform. Our rocker’s are also internally oiled (with the exception of our Sport comp rockers) The rocker arm will have oil holes drilled internally in the rocker body. You can see this hole behind the roller tip in the body itself.

Number’s on the side of the rocker

Our rockers do have a few different number’s on the rocker body itself. Back at the adjuster screw we stamp the rocker with a letter code. This is the actual ratio of the rocker arm. Here is a break down of the codes and their ratio.

The next is a 6 digit code on the side of the rocker arm. This is the month, day and year the rocker was built and shipped. When trying to I.D. the rocker’s this date can help us tremendously. If we know who originally purchased the rockers we can look it up under that customer’s history.

Here you can see the 6 digit number we are talking about. This rocker would have been built April 24th of 2014. If we know who originally purchased the rocker from T&D we can look them up under their history.

In recent years we have started putting a part numbering system on our rocker’s that is back by the adjuster screw. The letter code is the ratio listed above, The first number is the fulcrum length and the last is the amount of offset



In this picture you can see the build date being 042414 or April 24th 2014,

you can also see the “H” or 1.80 ratio code and 41 for fulcrum length and offset which is 1.650 long and on center