C5XTASY

I have a set of 2003 LS6 heads I'm installing and want to install a Comp Cam 216/220 (XR269HR) with them. However, I know the 2002-2004 LS6 valve stems are 0.6 mm (.024 inches) longer than LS1 valve stems. I have read that the reason for this is that the 2002-2004 LS6 cam has a base circle of 19 mm vs 19.7 for the LS1 cam, so the valve stem lengths were increased to compensate for that. Some questions:
1) How do I know if I need to adjust pushrod length?
2) How will I know if the physical relationship of lobe height, and valve duration, to the valve stem itself, has changed using the Comp Cam 216/220 with these heads vs the stock 2002-2004 LS6 cam?
3) If preload is affected, can it be adjusted properly?
4) What is the base circle of the Comp Cam 216/220?

I really want to do things right here and could really use some expert help.
Thank you.
Ed

PREDATOR-Z

I run LS6 valves in my LS1 heads with a stealth II cam and stock rockers using 7.35 p-rods.
For proper preload the best would be adjustable rockers.
My valvetrain noisenoise was not higher and judging by the power i made preload was fine.

Grimes

iTrader: (3)

I personally think that you will be fine using the stock pushrod length. Pretty sure the 216/220 has a smaller base circle, the difference being made up by the hydraulic lifters. So I think for the exhuast side, the smaller base circle will negate the slightly longer valve. For the intake side, the lifters should take up the slack. If you cannot get enough preload, you can just get slightly longer pushrods - but from what I read here, you should be fine.

BrentB@TEA

I would use a 7.400 and mill the heads .030 while I had them off

C5XTASY

Talked with Doug Rippie Motorsports (DRM), today and the proper pushrod length will be determined, once the heads and cam are installed, via measurements. Then I'll stay with what I have, or get what I need. Guess that is the best way, rather than trying to "guess-estimate" and buying parts I may not need. Thanks for all the help. I really appreciate it.
Ed