Head Gasket Advice

35th

Registered User
Going to be doing head gaskets in the next week or so never done head gaskets on an SC anything in particular I should look for or be cautious about or is it pretty straight forward?
 

ALS35

SCCoA Member
I've done that a couple of times. If you have stock exhaust manifolds, this would be the time to remove the restriction at the exit end. Also, pre-fit them to the heads before you put the heads on. They tend to change shape when you remove them and you need to relieve the forward and aft mount holes. Do not change the mount holes for the centre ports.
If you have adjustable rockers, you need to set them up correctly. I believe that Dave Dalke did a post that explains the procedure that he uses. It is critical that you do that right.
Change the oil! Run it a bit and change the oil again. You must get the antifreeze out of the oil. Yes, it will go in there!
You should contact Dave Dalke to get the part numbers for changing over to ARP studs. The stretchy bolts kind of suck.
The rest, as far as I remember, is straight forward.
Alan
 

jb351

SCCoA Member
I just did mine a couple months ago. It is fairly straight forward, other than a torque wrench and fuel line disconnects it does not require any special tools. Soak whatever fasteners you can see in some good penetrating oil ahead of time, spark plugs too. Hopefully the bolts broken will be minimized.

Here is a few things I recall about it.

For mine I used MLS gaskets and a heavy coat of copper spray on both sides (the block and heads were not resurfaced) and it has been fine so far. It did have studs installed already from a previous rebuild. I also copper sprayed the intake and exhaust gaskets and put a small bead of black rtv sealant around the water jacket holes in the heads/intake.

Be careful cleaning the deck of the block and avoid aggressive abrasive methods that can damage the surface or leave small particles (scotchbrite) in the cylinder bores. The intake bolts will need a thread sealant/locker. I used Permatex High Temp Thread Sealant for mine https://www.permatex.com/products/t...nts/permatex-high-temperature-thread-sealant/. Expect a few unexpected extras that may need to be done while the motor is stripped. Heater hoses and motor mounts are easy to change while the heads are off etc. If you are not going to pull the power steering pulley you will need a swivel for your ratchet to get the bolt out behind it.

If the injectors are factory and never been removed or serviced consider replacing the o-rings to avoid any potential fuel/vacuum leaks upon re-assembly. Rock Auto sells the kits cheap for them. Be meticulous about sealing things up to avoid potential vacuum leaks and be gently with the wiring harness and it's connectors. Take photos before, during and after and label anything that is not obvious, this can help with troubleshooting. If you are going to be painting things before it goes back together ensure that there is an unpainted spot where each part meets each other for ground connectivity. Also, while the engine is stripped down to the shortblock, avoid spraying the open and exposed engine and engine bay with a dry chemical fire extinguisher, this can be prevented by checking more carefully for flammable rags before using a torch on a stubborn O2 sensor and having your car go from Thunderbird to Firebird for a few moments while you run to your house for said fire extinguisher.

If you are running the stock exhaust manifolds do try and open up the exits like ALS35 mentioned. I put mine in a milling machine and bored them but you could also do it with a die grinder and cutters. A machine shop would probably do it quick and probably just cost an hours labour cost, maybe less.
 

Rick_Leuce

Registered User
I've done that a couple of times. If you have stock exhaust manifolds, this would be the time to remove the restriction at the exit end. Also, pre-fit them to the heads before you put the heads on. They tend to change shape when you remove them and you need to relieve the forward and aft mount holes. Do not change the mount holes for the centre ports.
If you have adjustable rockers, you need to set them up correctly. I believe that Dave Dalke did a post that explains the procedure that he uses. It is critical that you do that right.
Change the oil! Run it a bit and change the oil again. You must get the antifreeze out of the oil. Yes, it will go in there!
You should contact Dave Dalke to get the part numbers for changing over to ARP studs. The stretchy bolts kind of suck.
The rest, as far as I remember, is straight forward.
Alan

Crap, wished I would have known about modifying the exhaust manifolds before I replaced the headgaskets in my 1991 and 1993 SC.

My 1993 had coolant in the oil, I drained it and refilled it, I should probably drain and replace again even though it only drove 1,000 miles with that oil. I will say that I drained the oil, then when we were all done replacing head gaskets and reinstalled everything, I removed the oil plug again and got the last of the oil/coolant that had settled and collected at the bottom of the pan after a couple weeks. I did this right before refilling with oil, so hopefully only a trivial amount was still left. I should probably do another oil change anyways.
 
Last edited:

KMT

Registered User
Crap, wished I would have known about modifying the exhaust manifolds before I replaced the headgaskets in my 1991 and 1993 SC.

While the manifolds are off, in the example of early engines, if better exhaust flow is the goal, this is also a good time to swap the passenger side manifold for the later '94/'95 style. This change would of course dictate a pipe mod, which is a good excuse to move to hi-flow downpipes and cats.

I don't think it's a trivial job, so I'm not sure I'd put the effort into hogging out the outlet on an early pass. side manifold otherwise. But hey, it's just labor, so...
 

MadMikeyL

SCCoA Member
One quick tip I use on any larger jobs, get yourself a sharpie marker and a pack of zip-lock freezer bags. Put small parts or bolts for any particular thing in a bag and label it with the sharpie (Exhaust manifold, left accessory bracket, ps pump, alternator, etc). This takes only a few minutes and maybe $5, but saves all kinds of headaches knowing which bolt goes to what when going back together, and if for some reason once you get it apart you run into an issue where it may be a while before it goes back together, when the time comes to put it all back, everything is marked and categorized for you.

Also, if you can find a set of the teflon gaskets, that makes sealing up the intercooler pipes nice and easy. They used to be cheap on ebay, but they aren't being produced anymore, and so are hard to come by.
 

35th

Registered User
I appreciate all the tips I really do I'm gonna refer back to this post oh maybe a million times to make sure I understand all of this
 

FurryWrecker911

SCCoA Member
if better exhaust flow is the goal, this is also a good time to swap the passenger side manifold for the later '94/'95 style. This change would of course dictate a pipe mod, which is a good excuse to move to hi-flow downpipes and cats.

After spending weeks fighting the driver side cat heat shield, failing, and just using a thin crow's foot to bypass the shield blocking the manifold flange, I've seriously been considering teaching myself how to cut the cats off, get longer headers to make up the difference, and learning how to clamp them in place.
 
Top