BB Rocker Arm Markings

[Ted S.]

I was looking at 3 different sets of stamped GM BB rockers I have and they all have different markings on the valve end. One set has no marking, another set has an "L", and the other set has an "N". Are these different manufacturer marks or do they specify the application (i.e. 427-390HP vs 427-435HP) or ??? Thanks in advance for the help. Ted

[Joe L.]

Re: BB Rocker Arm Markings

Ted------

There were different rocker arms used for different big block applications over the years. Here's the deal:

"no marking" rockers-----these are most likely aftermarket pieces. Most aftermarket are unmarked. However, I believe that they may also be GM #3860305 which were used for 1965-72 non-SHP applications;

"L", "Z", or "X" tip marking----GM #3860308. Used for 1965-69 with SHP and 67-E69 L-88. Also, replaced the 3860305 for SERVICE effective February, 1972;

"M"-----GM #6258611-----used for 1973-74 all big block. Also, became SERVICE for 3860308 effective Novemeber, 1972; currently replaced by GM #10112680

"H"-----GM #3959182---used for L69 L-88, all 1969 ZL-1 and 1971 LS-6. Currently replaced by GM #12368082 which is a kit which includes 1 GM #3959182 rocker + ball and nut.

There was no "N" that I know of; you may be mistaking a "Z" or an "M"

[Ted S.]

Re: BB Rocker Arm Markings

Joe, Thanks for the fast response. The "N" could easily be a "Z". If I look at it from the tip it's a fat "N" from the side it's a normal "Z". The "L" is read from the tip so I figured the "N" was also read from the tip. What you said makes sense because I belive the L and Z rockers are off of L78s and the non marked ones I believe are off of a '70 350hp 402. Thanks again. Ted

[Mark S. Lovejoy]

Re: BB Rocker Arm Markings

Hey Joe,

Would the "H"--GM #3959182 rockers be suitable for the '65 396/425 we are building?

Thanks,

Mark

[Clem Z.]

"H" are good for .600 lift cams

check the rockers where they contact the valve stem tip and check for wear if these are used ones. if you need to replace any put the new ones on the intake and put good used ones on the exhaust because of the heat that travels from the exhaust valve to the rocker ball. also use moly kote to prelube the balls and rockers. if you did not keep the balls with the rocker they were used with you will have to adjust the lash more often till they mate in

[Joe L.]

Re: BB Rocker Arm Markings

Mark------

Yes, they'll work perfectly. Also, you can purchase a whole set of these under GM #12368085. This includes 16 of the 3959182 rockers + rocker balls and nuts.

[Mark S. Lovejoy]

Re: BB Rocker Arm Markings

Thank You Joe, I appreciate the help.

Best Regards,

Mark