FWIW...

I believe the OEM fixed length pushrods shoot for a lifter preload around 0.100", or half the hydraulic lifter "range".... The cylinders grow when hot, so the cold lifter preload always decreases with engine heat. That's why the MoCo went with the hydraulic lifters from the solid tappets of yesteryear...

There are some very smart HD techs who say that when using hydraulic lifters, it really doesn't matter what the preload is (within reason, say 0.100" - 0.145") because the lifter adjusts...

There are some very smart HD techs who say they always set adjustable lifters at 0.140"-0.145" and they have no issues with noisy top ends...

There are some very smart HD techs who say if the top end is noisy after a cam change, bump up the preload to 0.140" and the top end will quiet down...

I don't have anywhere near the knowledge or experience of the techs making these claims, so I can't say what the best answer is... It makes my head hurt just thinking about it..... But I figure if they are ALL right, then it can't hurt to set the lifter preload at 0.140" ....

But then, there are also those who claim it never hurts to run travel limiters in the lifters..... That is a different discussion for another day...

 

 

...to a one year old thread?

 

I was sure someone would bite. I was just trolling around. 👀👁👁👁👁🙌🏻 LOL