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Discussion Starter #1
I finished my dod delete 3 weeks ago but had to go to work( I work in Canada 2 weeks on and 2 off) and ran out of time to do some final checks, but i knew with my stock rockers i was running a little too much preload on my lifters. So i decided to go with these.

They arrived yesterday, I pull off the stockers, install the base, back off the adjusters all the way, put the cam on the base. I go to install the rocker and shaft but before it even comes close to the shaft seating, I hit zero lash. So I'm scratching my head because i was told by comp and lunati that this setup will be fine.

The setup is 228/240 612/612 cam, lunati high speed link lifters, 7.400 push rods, the comp cams rockers you see and lunati .650 springs and heads are milled .015.

At first i thought the lifters might have a higher cup height so i call lunati to find out. They tell me it's only a .007 difference and that i need to let the lifters bleed down. I'm still not sure about this info because it seems excessive....here's why:

I don't have a rod checker so i improvised. With the base bolted down, I set the rockers in and start screwing down the shaft nuts untill i feel zero lash. The shaft is nowhere near seating to the base. So while it is in that position i measure with a depth gage the top of the shaft stud to the top of the shaft hold down nut. I then take the rocker back off, remove the pushrod so i can seat the rocker shaft. I then do the same measurement from the top of the stud to the top of the nut again and the difference is .300.

The lunati lifters only require 0.010 to 0.015 preload. My next step would be to install them anyway and let them set overnight to see if the lifters will bleed out but i am afraid of overloading the lifters and i also leave for disney today and don't want them sitting like that for a week just in case.

I guess i'm looking for some advise as to weather these lifters will bleed down that much or that i need shorter rods.

Rick you out there??

Thanks.
 

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Now what lifters were Lunati comparing their lifters to? Stock or LS7?
LS7 have a .050" higher pushrod cup height than our stock lifters.
With a new cam, lifters, and rockers, you can not guess what length is right. You need to measure. Even with adjustable rockers, the Lunati have
less internal travel/preload. Pushrod lenght has to be right.
Your heads being milled, that .015 has to come off the pushrod length.
Buy or borrow a pushrod length checker, $20. That way you can get the exact preload.
 

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Discussion Starter #3
Believe me i know, that why i figure they are totally WRONG. I plan on getting a checker when i get back. Im guessing with the way i measured, I will be pretty close, but that's still not enough for me. Like i said, if i do a mock zero lash check, my shaft is still .300 off the seat, that's with the rod adjusters backed all the way out, so i will have to split a little more difference for that as well. So if i'm right it looks like my rods will have to be somewhere around 7.000 to 7.250 depending on how far i set the adjusters.

Now if i'm wrong, and these do work, i would have to install them, let them bleed down and i should have clearence for the adjusters.....but i don't think so.
 

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Might be the pushrod length. Im having the same problem im running 7.4 pushrods,stock rocker arms and ls7 lifters. And i am getting lifter issues with some ticking so im guessing it has to do with the lifter preload. I already order the checker to make sure everything is correct.
 

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I'm confused

It seems like everything I've read is people are using 7.4 or 7.425 pushrods. But if the LS7 lifters are .050" higher, wouldn't you then need <about> 7.35? Is something else needed besides an adjustable length pushrod and then center the tip on the valve throught its motion?
 

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Discussion Starter #6
Had a buddy make a checker for me, real heavy duty. He is a pro engine builder and told me that the way i was checking difference should be damn close. So when i get back from my trip, all I will need to do is clearance the inside edge. Some of the rockers are interfering with the body. And I remove the baffles.
 
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