69 L-71 Rocker Arms

[Dan M.]

Can someone tell me the difference between what appears to be a stock set of rocker arms some are stamped with a "L" and some with a "W". They look the same to my eye except for the stamped letter.

As always thanks for your insights in advance

Dan NCRS # 35068

[Joe L.]

Re: 69 L-71 Rocker Arms

Dan------

Originally, 1969 Corvettes with L-71 and 1st design L-88/ZL-1 used rocker arms GM #3860308. These rocker arms had a debossed "L" or "Z" on the valve end. These were later replaced for SERVICE by GM #6258611. The latter rocker arms may have a "W", although I am not certain of this. Except for the debossed letter, both of these rocker arms should be near identical. In any event, I would expect that some of your original rocker arms may have been replaced by the GM #6258611 at some point along the way.

Incidentally, 2nd design L-88 and ZL-1 used a different rocker arm. This arm was GM #3959182 and is identified by a debossed "H" on the rocker arm valve end. This rocker arm has a longer rocker stud slot to accomodate higher lift cams without damage to the rocker fulcrum. Although originally used on L-88 and ZL-1 only, these rocker arms can be used on any big block although they serve no real purpose for lower lift camshaft profiles.

[Joe L.]

Addendum

By the way, the GM #3959182 rocker arms are today known as GM #12368082. This is actually a "kit" which contains the 3959182 rocker arm (with the "H" debossment) PLUS the rocker ball and rocker prevailing torque nut. The original 3959182 rocker was supplied without a ball and nut. After about 30 years GM figured out that it would be more convenient for folks if a rocker ball and nut were supplied with the rocker. Very few folks use a new rocker arm with a used ball and nut. At least, I hope that very few folks do.

Also, the GM #6258611 (which was supplied with ball and nut) is now known as GM #10112680, which is also still supplied with ball and nut.