What should be done if you purchase used heads? ---

[alwayscode390]

Is there anything that MUST be done if you purchase a set of used heads before installing them?

I had a set that someone blew a head gasket on after 1500 miles ... I was told to get them resurfaced just incase the heads werent totally flat.

Is that a good thing to do no matter what on a used set of heads ... to get them checked for flatness?

What else to look for if dropping them off at a machine shop ... cracks anywhere from shipping? Do they have a test they do to find cracks ... or do they just look in the most prone areas of the heads?

How much does a machine shop usually charge to do a "one over" on a set of heads ... even if work isnt performed ... or they totally disassemble and reassemble them?

Thanks

---

 

[Jerryl]

You should always do a full R&R if you do'nt kow the history, especially the springs and verify all other specs.
As far as cost . . . . the correct answer is "it depends".
I had a set of heads completely redone for around $350, but I supplied all the needed parts.

 

[BEATAV8]

A good machinist will know what to do. It will start with inspecting EVERYTHING.
You cannot make a call on what needs to be done until the parts are inspected.
-magnaflux to check for cracks
-check deck for straightness / flatness. Surface finish may also be important depending on the head gaskets you want to use.
-check valves and valve guides for proper TURBO clearances (typically much looser than N/A applications)
-check valve job / valve seats
-check spring pressures open/closed for match up with your camshaft application

Once everything has been inspected, you will know what you got and what needs to be done. If they are cracked, they're JUNK. Get another set. All of this inspection work might cost a couple hundred bucks. It will vary shop to shop. I use a local shop that doesn't charge me too much for inspection, but we have a good history going back several years.

 

[alwayscode390]

Can the machine shop test to see the spring rate? Thanks for the heads up on the TURBO specs being looser, I will keep that in mind ---

 

[SuperSix]

Can the machine shop test to see the spring rate? Thanks for the heads up on the TURBO specs being looser, I will keep that in mind ---

Yes. They have spring testers.

 

[BEATAV8]

Can the machine shop test to see the spring rate? Thanks for the heads up on the TURBO specs being looser, I will keep that in mind ---

Yes, they should be able to measure the spring pressure "closed" and "over the nose", or "open". Your cam card will tell you the required spec for your cam.

 

[charlief1]

Make sure that the stems are at the same height as well. Most shops these days don't check for this so you may end up with different heights and that will cause issues.

 

[Guess]

How much does a machine shop usually charge to do a "one over" on a set of heads ... even if work isnt performed ... or they totally disassemble and reassemble them?

My local machine shop disassembled mine and checked for cracks. I think they charged $57.

 

[alwayscode390]

Someone else mentioned just getting the shop to disassemble them ... why not have them put them back together too? Just curious , thanks ---

 

[oldsracer]

Where are you located. Maybe someone can point you to a shop they know or use regularly

 

[Smokin-6]

I bought some used heads and had them checked for crack, they also gave them a valve job and new seals. Cost around $400.

 

[charlief1]

$400 for a crack check and valve job? I usually get one head done with a 3 angle for about $125 unless something needs replacing. I get a crack check and full cleaning here for $50 a pair.

 

[bison]

Yes, they should be able to measure the spring pressure "closed" and "over the nose", or "open". Your cam card will tell you the required spec for your cam.

The cam cards are about useless for spring recs . They seem to be for NA applications. Reading posts on here will give way more info on spring pressures needed. They rec about 120 on the seat for a common 212 grind. Good luck with that if the engine will make enough power to pull to 5600+ and 28-30psi.

 

[Guess]

Someone else mentioned just getting the shop to disassemble them ... why not have them put them back together too? Just curious , thanks ---

I wanted mine checked for cracks before I ported them. They put them back together afterwards.

 

[alwayscode390]

Where are you located. Maybe someone can point you to a shop they know or use regularly

I am in Saint Louis ... going to a performance shop Thursday , I will ask if they know anyone close by that they recommend also ... THANKS ---

*** One set of heads is Champion ported IRONS for the TTA
*** Another set of heads is a ported big valve Vortec IRONS for the Syclone (possibly DLS)