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I am going to pulling the heads on my Impala soon to remove the exhaust manifold bolts that are stuck in there. Taking the heads to a machine shop so they can remove the bolts and check all the threads for me, some of the bolts as I pulled them out were bent and I believe they may have ruined the threads. I will be doing the throttle body coolant bypass while I am there. I live in the south and the car is stored during bad weather. Car also is losing weight. I do have a few questions about this process though. Keep in mind the car has 135k miles on it.
Should I have them clean the intake manifold and the throttle body while I am there or should I just carb clean the hell out of both and call it a day? I am pretty sure my intake manifold is leaking oil right now so I want to make sure everything goes back together real nice and pretty like.
Should I get the intake ceramic coated like my headers are?
Is there a way to get the EGR studs off of the back of the intake?
I will list my parts below and you can let me know if I am missing something.
My parts list right now
Head Gaskets Mr. Gasket 5716G
Head Bolts ARP 134-3601
Intake Manifold Gaskets GM Genuine 12524653
Bought exhaust stuff for the header install in different thread
Valve Cover Gaskets Fel-Pro VS50088R
Throttle Body Gasket GM Genuine 407018
I have had a lot of recommendations to change valve springs and to change valve stem seals. The car does not burn oil right now so my dilemma is that, I change the steam seals and they suck and boom it leaks OR I don't change the steam seals and then they start leaking. This is an iron headed LT1 btw
The only reason I am hesitant to change springs is because this is a stock motor that basically will remain stock forever minus the headers and a tune. Don't want to dump too much into it.
Last edited by shakenfake; Aug 2, 2022 at 09:42 PM.
Should I have them clean the intake manifold and the throttle body while I am there or should I just carb clean the hell out of both and call it a day? I am pretty sure my intake manifold is leaking oil right now so I want to make sure everything goes back together real nice and pretty like.
Clean them yourself. Just know the way the pcv system/breather tube is designed it's going to get sprayed with oil unless you want to put a canister between the valve cover breather tube and the port on the throttle body.
Should I get the intake ceramic coated like my headers are?
I've never heard of anyone ceramic coating an intake. Powder coating and painting, yes, but not doing a ceramic coating.
Is there a way to get the EGR studs off of the back of the intake?
IIRC you'll have to get an inverted star socket to get them out, or try and use a 12-point that will fit over them.
As far as your springs are concerned, it wouldn't hurt anything to at least have the shop test the springs to ensure they still have good pressures, and while you're at it, put on some new valve seals.
@SS RRR I am unsure what you mean with your first point. Are you saying there is always going to be oil going into the intake? I just wanted to clean them real quick so everything looks nice when I put it back together lol
Apparently someone on the Impala boards put on high temp sealant on the inside of the manifold and it helped prevent heat soak and gained them .2 seconds in the quarter mile. This guy is pretty legit over there so I believe what he says is true. I figured the ceramic header coating would do the same thing. It is something I have talked about with my coater before.
Ah inverted star good thought, I haven't taken it off so was just hand feeling around back there. I have a few of those and can always use more tools
Yeah that is what I figured I would do is have the shop test them. I will have to order some valve seals.
@SS RRR I am unsure what you mean with your first point. Are you saying there is always going to be oil going into the intake? I just wanted to clean them real quick so everything looks nice when I put it back together lol.
The breather tube, located on the passenger side going into the throttle body is the main source of oil saturation on the inside of the intake since it is neutral flowing. The baffling on pretty much any center bolt valve cover isn't really enough to stop it from happening. People have put oil separator or catch can (canister is the wrong term) in line with the breather tube to filter out oil from getting into the intake.
I did this recently on my 95 Z28 and here's all the stuff I ordered. Looks like you have the main things covered. One thing that made a huge difference was swapping out the header bolts to ones with a smaller bolt head size for easier access.
Head Gaskets Mr. Gasket 5716G
Header Gaskets Fel-Pro MS95585
Header Bolts ARP 100-1109
Head Bolts ARP 134-3601
Intake Manifold Gasket Fel-Pro MS95580
Valve Cover Gaskets Fel-Pro VS50293R
Coolant Crossover Bolt GM 12552974 (I'm sure you can re-use the existing)
ARP 7/16 Thread Cleaning Chaser ARP 911-0004 (to clean the threads in the block that the heads will bolt to)
Here's a list of all the fasteners and torque specs for the job that I ran across. Hopefully it helps:
Thank you so much!
I have some header bolts but I do not remember the ARP part number, I believe they are the same as yours although they are a polished look if I remember correctly.
I decided to try and remove the stuck bolts myself first before taking it to the machine shop. We'll see what happens. Still pulling the intake manifold no matter what though, that thing needs new gaskets and a cleaning.
You can clean the intake manifold yourself. Simple Green, brush, repeat as needed. TB ONLY use TB cleaner (read not carb cleaner)
at 135k mi your stock valve springs are beyond done, Replace. Crane drop in kit is long gone. Send Lloyd Elliott a email asking what iron head springs he likes. IIRC Howards??...maybe PAC.
Consider adding 1:6 SA RR...poor mans cam. If using other than 3/8" Crane Gold "narrow body" RR, you will need to trim the baffles, intake side, on VC. Simple mod
absolutely replace valve stem seals. FelPro Viton ones. Most auto part stores have them and doing springs, it's part of that job. Heads off its simple
Coolant bypass, sure, simple mod
replace PCV and the PS hose if original. The insert on DS intake for PCV may aso need replacing if original
Get the Harley rubber washer for MAP
Use Permatex Black Ultra RTV on the china walls for intake. I prefer the FelPro "printo" seal intake gaskets but GM are also fine you got
if machine shop can extract broken iron manifold bolts you can put your stock ones back on. Otherwise go headers which use the other open bolt hole on heads
At this point given heads are coming off have machine shop lap valves assuming no guides need replacing. New valve springs and seals are a must
EGR...well if you insist on removing it, no reason to, than just get the EGR block off plate. Your pcm will need a reflash so the CEL won't come on for EGR delete. EGR has zero impact on performance
I tried getting in contact with LE but never got a reply back, I may hit him up one more time later.
@****** Do you mean Harley like Harley Davidson? That's what I get when I look that up lol
I have FLP headers going on, main reason for this whole exercise. The bolts are broken off in the holes that the headers need.
I just want to take the studs off the back of the intake to use these nicer bolts I have for the EGR. I can neither confirm nor deny that I am removing the EGR
No question you want to do valve springs and new seals
EGR....with headers and freer flowing than stock exhaust you want the F body 6 speed EGR unless the delete is because headers are non EGR and I assume emission testing is not a issue for you. You would need a PCM program to tune out EGR so at that point get a performance tune, 160 T stat and enjoy the HP gain that, headers and new valve springs will provide along with 1:6 RR
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Intake manifold and head removal 
