Cost to rebuild GM pushrod 3.1L V-6 heads?

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I'm in the process of replacing cylinder head gaskets on my '96 Grand Prix. I'm stuck on whether to take the old heads to a machine shop or buy rebuilt ones on Rockauto or elsewhere. Rockauto has the same head I need, rebuilt with valves & springs installed for right at $200 each.

I had a set of heads rebuilt and resurfaced on my '04 Odyssey a few years ago and IIRC, it ran me about $450. I have a hunch that an OHV (pushrod) head should be cheaper than the 24-valve Honda head. Anyone know a ballpark on what it might run for 2 heads off a GM 3100 V6?

If price was equivalent, is there any advantage/disadvantage to an off-the-shelf rebuilt head, or having my own rebuilt at a machine shop? I don't know the condition of these heads other than that the engine was overheated. The previous owner rigged the cooling fans to run all the time, so they likely overheated the [censored] out of it. I suppose them having cracks isn't out of the question. Some part of me wants to support a local business, but with the Corona going on, maybe it's just easier to click a button and have rebuilt heads dropped off on my doorstep? Curious what you guys think if you were given the choice between the two options.
 
I would go off the shelf. Quick, less fuss and like you said, dropped at your door.

Had heads crack on a 3.4L which needed rebuilt heads. No overheating.
 
The only advantage to going local with the rebuilding of cylinder heads will be getting the Bad News about cracks / need for another core.
I've shipped heads out for rebuilding & it's worked out fine other than the occasional tweaked exhaust stud thread or two.
I've also used a local cylinder head rebuild specialty shop & turnaround was quick. The head in that case was so distorted it required straightening as well.
Good thing it was a local shop & they were quick to point out what the additional charge would be to make things right..... extra 85 took the cost to $420 or so.
Sometimes it's best to go local if you have real heat damage on aluminum head versus cast iron.
I'd happily use RA for rebuilt iron heads.
 
The shop I used to work at to go through a set of 3.1 heads would be about $200 for the pair. Cracks between the valves are normal and there's not water there to leak. Mill, valve job, new seals, good to go for a long time. I woukd do them locally, if one is bad, mail order a replacement.
 
Is the 3.4 head a direct bolt-on? Or maybe even the 3.5/3.9 heads?
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Swap time
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On the social side, it's good to support local businesses when you can.
 
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Originally Posted by atikovi
How many miles and why do you think they need to be rebuilt? Why not just replace the oil seals and maybe lap the seats yourself?


Because the engine was overheated severely enough to trash the head gaskets, not going to go through all this work to put back suspects heads that might be cracked, warped or worse. I lack the equipment and expertise thoroughly check them, for $400 (likely less) to make the top end like new, it's an easy decision.
 
Unless this 24 year old car is pristine, you might be throwing good money after bad. Have you checked on what a good running example might go for? Or maybe try some Blue Devil first.
 
Are those iron or aluminum heads? On my 92 Olds with 3.1, iron and aluminum are available.
 
Originally Posted by atikovi
Unless this 24 year old car is pristine, you might be throwing good money after bad. Have you checked on what a good running example might go for? Or maybe try some Blue Devil first.

I agree, this car needs to be nearly perfect or have some sentimental value to be worth putting that kind of money & work into. I think I would be pricing a reman long block engine for it too.
 
Originally Posted by bullwinkle
I agree, this car needs to be nearly perfect or have some sentimental value to be worth putting that kind of money & work into. I think I would be pricing a reman long block engine for it too.


I'm afraid I don't agree. When it's all said and done, I'll probably have $2k into this car (price of car and parts) and will have gone over everything in the engine bay, taking steps to ensure it's reliable and leak free. Hard to find a reliable, running car for $2k and the amount of work doesn't bother me as it's more a hobby than anything-- I need another car like I need a hole in my head, but these cars are getting rare and this particular one is in reasonably good condition.

Remember cars around here don't turn into rusty heaps after 10-15+ years like many of the places you guys come from... The key is finding an older car that isn't already trashed out by some previous owner-- people are slobs and I'm amazed how awful most 10 year old cars look like compared to my 20+ year old ones. I don't think it's unreasonable to expect 3-4 years service out of this rig before something major goes wrong with it.... But it could certainly prove me wrong-- I've made far worse choices in my life!
 
Originally Posted by Trav
I would pull the heads and check the cylinder walls before ordering anything for this engine.


I pulled the heads already which didn't reveal anything unusual; looks like normal wear. Engine was running fine before disassembly other than overheating, burping coolant out the overflow tank, and slight oil/coolant mix. Head gasket autopsy reveals a leak between the water jacket and cylinder on two cylinders (of one head.) Typical head gasket case, intake manifold gasket could have contributed to the whole thing, but it will be replaced regardless. Compression was good on all cylinders despite the HG leak.
 
Originally Posted by IMSA_Racing_Fan
If there's no cracks then get a head gasket set, spray with copper gasket paint and go. Why waste money?



OP states it was overheated. When overheated, you need to check the heads and most likely resurface, especially with aluminum heads. Otherwise you blow another gasket.
 
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2or 3 hundred dollars to have the head cleaned, straightened, surfaced with correct finish for th deed gaskets to save all the labor. Good deal for me. If a good local shop, even better.

Rod
 
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