ChuckD

Just put a set of 241 heads and an LS6 cam in my 99. New lifters, push rods and valve springs too.

When I drive normal at freeway speeds its all good. Even when I'm on side streets and running it hard it's good. When I'm at freeway speeds and I run it up when I get out of the gas I can hear valve train noise, more specifically rocker arm tap.

The heads had 20 thousands taken off of them when they were surfaced and I have new 7.400 push rods. I've been told to shim the rockers .015 on the side thats tapping cause the lifters are having a hard time pumping up. Does that sound about right? Any other sugestions? Tips?

Darkman

iTrader: (2)

Did you check the wipe pattern or measure the preload that results for those pushrods?

garygnu

how many miles on the rocker arm trunnion bearings?

ChuckD

about 50xxx.

no, did not measure the preload

I asked the guys at SAM they recommended the shims

Darkman

iTrader: (2)

In that case. I would check the wipe pattern and add/subtract shims as indicated. Once the wipe pattern is acceptable the proper preload should be set using pushrod length. You may, or may not, need shims or a different length pushrods but it should be checked.

As garygnu suggested, you may find faulty trunion bearings in the rockers as an alternate cause while checking the other valvetrain components.

01ssreda4

iTrader: (96)

Gonna be mandatory to measure pushrod length in this case.