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Help please? TPI/Vortec head bolt/valve spring questions.

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Old 09-11-2015, 10:16 PM
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JHX
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Help please? TPI/Vortec head bolt/valve spring questions.

Putting vortec heads on my L98. I have a used head bolt set from a 96 pickup with these heads.

1) They aren't TTY, right?

2) Why is the tightening sequence changed from the previous? It's not just X ft lbs. It's now so many ft lbs + X degrees. Can't I just torque them the old way? What's the difference?

Heads are new GM #12558060

Same as these, actually:
https://sdparts.com/details/gm-perfo...parts/12558060

The cam is a Lunati Voodoo. 213/219 - .454/.468
http://www.lunatipower.com/Product.aspx?id=2323

Do I need to check retainer clearance or spring bind with this? If so, what's the easiest way to do that? How can you tell is a valve spring is binding? If the coils touch? Is there some minimum distance I should be looking for here?
Old 09-11-2015, 10:23 PM
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Re: Help please? TPI/Vortec head bolt/valve spring questions.

I would not reuse the 1/2" head bolts as I have had one break in the past. The older 5/8" ones I only reuse once. You can get a new set of Felpro head bolts for under $50.00. They come boxed for one head, so you need two boxes (about $20-25 each) Cheap insurance against having to do it over again. I have always used the older torque method. I go in 3 steps, 45-55-65 ft/lbs. Have not had an issue yet.

As for lift for the stock head, I don't even check until I get around .490". The Ramjet 350 has .459/.481" lift with its 1.6 rockers on a production head.

Last edited by Fast355; 09-11-2015 at 10:26 PM.
Old 09-11-2015, 10:25 PM
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Re: Help please? TPI/Vortec head bolt/valve spring questions.

^This
Old 09-11-2015, 10:30 PM
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Re: Help please? TPI/Vortec head bolt/valve spring questions.

Further improving my point about used head bolts, the factory GM bolts are even cheaper than the Felpros I usually use.

https://sdparts.com/details/gm-perfo...parts/12495499
Old 09-13-2015, 06:44 PM
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Re: Help please? TPI/Vortec head bolt/valve spring questions.

TY, sir!
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