Does anyone know how much open seat pressure you can run on stock ls1 rockers with a trunion upgrade? I have a set of comp dual springs here that I could throw on my heads but I'm not sure if 400 lbs of open seat pressure is too much for stock rockers. Also, the valves I have are .100 longer than stock. I was thinking of running them with a .100 shim. Would this adversely effect my rocker/pushrod geometry? Thanks for any help!

 

I believe 400 lbs is the recommended max open load pressure(valve open). I'd also set the installed height(valve closed) to what is recommended, so only shim them if needed to set them to the recommend seat height. The .1" longer valve stem will translate to needing about a .059" shorter PR's. I'd also try and keep the lift to .630" or less.

 

The cam I have is .605 lift so I should be fine there. I have heard you can take the stock rockers to 7500 rpm. I would like to hear from someone who has done it. How long might they last like that?

 

I have ran to 8k without problems. The key is strong pushrods for valvetrain stability.