checking push rod length
 

almost finished building my 408, just need to figure out what push rod length i need.

i have ls3 heads with ls9 cam.

picked up a push rod measuring tool and im not sure 100% on how to use it.

any info on how to measure for push rod length would be awesome.

Thanks guys.

If you got the tool that most of us do, it's pretty simple. Each full turn adds 0.050" of length. Lengthen the rod a little bit at a time, install the rod, install rocker, tighten rocker bolt. Repeat until the rocker is at zero lash right when the bolt is fully tight. Try to get within 1/4 turn accuracy. Then pull out the rod and count the tuns until the rod is fully short. Then do the math: Base length plus number of turns times 0.050" plus desired preload.

For example, lets say you counted 10.5 turns, base length is 6.8", and you want 0.075" preload.

6.8 + 10.5*0.050 + 0.075 = 7.400"

Do this for a couple other rockers to make sure you get the same results.

Thanks for the info, ill figure out what i need tomorrow :)

I finally got around to measuring my pushrods, I just want to confirm I did it correct.

I got 9 1/2 turns for zero lash, this length is 0.475?

Base length of the tool is 6.8 and I want 0.060 preload?

I ended up with 6.8 + 0.475 + 0.060 = 7.335?

let me know guys, Thanks!

Anyone?

Yup that right! I'd go with 7.350" pushrods for a little more preload.

Thanks :)