Ok fellas,

With the great help of some users and vendors on this forum, I am about to complete my 6.0 build for a fun street truck. However, I am stuck on my pushrod length. I will go through a list of what I have used and done to try to answer some questions before they are asked. Here goes:

I had a camshaft spec'd by Pat G. and was made my Texas Speed. I spoke with Lonnie Fowler at Texas Speed and got the camshaft and valve spring kit together as a package. They also included new hardened pushrods. The length was based on what we thought it would take to get a compression ratio of 11 using the parts of my build (243 heads...etc.) Lonnie came up with 7.375

This phone call was made BEFORE my builder did any work to my heads. Once my builder was finished he informed me that my heads only needed to be milled 15 thou rather than the 30 thou we (Lonnie and myself) figured to achieve the CR of 11. So....Does this change the length of the pushrod needed???

I have bought a comp cams pushrod checker and I have searched youtube and here trying to find a concrete way to make sure I have the right length. However, this is my first build and I am honestly not sure WTF I am doing. I can't seem to figure this **** out. Can anyone offer me some advise...links...anything would be helpful.

If I left out any info..just tell me and I will do my best to tell you. Hope I explained it well because I am frustrated as hell.

 

In short, not really. It just changes your lifter preload. If you are still within an acceptable range of preload you're fine.

 

Check your preload. It still may be within spec

 

Check your PR length. No 2 ways about it. It's not difficult just a bit time consuming.

 

I've got what I think is correct PR measurement...but I honestly am not sure. What should my preload be for LS7 lifters?

 

Here's a good video on checking pushrod length using the adjustable pushrod. GM lifters are pretty forgiving, but common practice seems to indicate 0.070" preload on the LS7 lifters.

 

I used that EXACT video last night when measuring. Soo.....I assume I am on the right track. However, I also watched a video from Comp Cams stating that I should have 1/2 to a full turn (of the rocker bolt) ?? I have maybe a 1/4.

 

I've ran 1/4 turn before no probs

 

I found Comp Cams information to be pretty crappy. I have been told things by their tech support that are just flat out wrong. I don't call them anymore if I have an issue.

As far as turns of the rocker bolt, you should use the adjustable to measure as shown in the other video and use those numbers. Bolt turns are not an accurate way to measure.

 

Hi 79, you can use Math.

State your camshaft Base Circle Diameter ?
State your Head Gasket Thickness ?

Then compare to your findings.

Lance

 

1/2 turn in his video is 0.040" preload. A little on the light side IMO. Note that in the video he is using the bolt rotation until the rocker seats. He does not torque the rocker down. That will add about 1/3 turn.

 

i would use the length checker tool and a pair of good digi calipers over the turn method.