• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

GT40P head gaskets, intake gaskets

  • Thread starter Thread starter nunly94gt
  • Start date Start date Mar 21, 2009

nunly94gt

Founding Member
Feb 3, 2002
1,595
3
38
Mobile, Al
Mar 21, 2009
#1
  • Mar 21, 2009
  • #1
More of a curiosity question than anything, also for reference later on.
Im about to get my hands on some GT40P stuff and was wondering if I need to order gaskets for 19** Explorer or what?
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,216
17,899
224
Massachusetts
Mar 21, 2009
#2
  • Mar 21, 2009
  • #2
Ask for gaskets, spark plugs and exhaust gaskets for a 1993 Cobra
 

nunly94gt

Founding Member
Feb 3, 2002
1,595
3
38
Mobile, Al
Mar 21, 2009
#3
  • Mar 21, 2009
  • #3
thank you very much sir!!
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Mar 22, 2009
#4
  • Mar 22, 2009
  • #4
Cylinder head removal & replacement, all types of heads on a 5.0 Mustang

Plan on 3 days to do the job if you haven't done it before.

Day one gets the heads off in 4-6 hours. Remove the A/C compressor mount bolts and move the compressor out of the way.
The A/C compressor swings out of the way without disconnecting any of the lines or losing any refrigerant.
Mark all the electrical, smog and vacuum lines with tags to help you remember where to re-connect them.

Day two gets all the gasket surfaces scraped off extra clean and the heads dropped off at the machine shop if you are going to
have them reconditioned. Time here is another 4-6 hours. Whatever you do, don't skimp on cleaning the gasket surfaces.
New gaskets need to seat against bare metal and not the residue left from the old gaskets in order to seal leak free.
This is the most time consuming and tiresome part of the job. Look for little things that need to be replaced like the short
hose from the thermostat hosing to the water pump, damaged vacuum lines and hose clamps that are rusted or broken.

Day three starts when you get the heads back from the machine shop. This is the time to pick up all the little odd pieces
you found needing replacement on your day two inspection/cleanup. Plan on 6-8 hours to reinstall the heads and reconnect
everything. Plan on an additional 2 hours to troubleshoot/adjust everything.

Now for some practical tips:

Plan on cutting the thermostat to water pump hose, or removing the thermostat housing. Also plan on removing the distributor
to get clearance to remove the intake manifold. Remove #1 spark plug, stick your finger in the spark plug hole and crank.
When your finger gets air moving past it, stop cranking. Turn the engine until the timing marks line up with the pointer.
Make a scribe mark on the distributor base and engine block. Now you can pull the distributor out. When you re-install the
distributor back in the engine, make sure you are still on TDC compression for #1 and then line up the scribe mark on the
distributor and engine. You will be very close to where the engine was timed when you took out the distributor.

You'll need new head bolts - get ARP bolts ($40) or studs ($93, maybe more). The ARP bolts have a radius under the heads.
The washers that come with the bolts have a chamfer cut in them. The radius under the bolt head mates up with the chamfer
on the washer. Fail to do this and the bolts will never torque down properly. All the bolts get antiseize under the bolt heads,
and everything but the short head bolts get it on the threads. You need Teflon pipe dope or ARP sealant to coat the threads
of the short head bolts. The short bolts go into the water jacket and will seep coolant if you don't use the sealant.

My favorite trick that saves time and effort is the stay in place gasket. Be sure that you scrape (don't use a wire brush) all
the old gasket material off, then clean all the surfaces with acetone or MEK.

When the surfaces are clean, use weather strip adhesive on the head to manifold surface, and on the side of the gasket that
mates to the head. Follow the instructions on the tube or can and when it gets tacky, press the gasket down on the head.

Clean the area where the rubber rails mount to the block in front and in the rear with more acetone or MEK and do the same
trick with the weather strip adhesive that you did to the heads.

Coat the rubber seals and the gasket area around the water passages with lots of Blue Silicone gasket sealer and put it together.
Walla! No leaks and no gaskets that shifted out of place.

If you reuse the injectors from your old setup, a repair kit is available from most auto parts stores if needed. Coat the injector body
"O" rings with oil before you use them and everything will slide back together.

For iron heads, clean the combustion chambers with a wire brush in an air or electric drill. I used a scraper for the pistons.
I don't like to use the wire brush on pistons because it will remove metal very easily.

Change the oil once you get everything back together. Once the engine is up & running, run it for 1-2 hours and change the oil.

Tools: a good torque wrench is a must have item. A razor blade scraper that holds a single edge razor blade from Home Depot
or Ace hardware is another handy thing. Get a Chilton or Haynes shop manual - you'll need it for the bolt torques and patterns.
The intake manifold has an especially odd pattern. You'll need access to a timing light to set the timing after you re-stab the distributor.

Consumable parts:
Fuel injector seal kits with 2 O rings and a pintle cap (Borg-Warner P/N 274081) are available at Pep Boys auto parts.
Cost is about $2.74 per kit. The pintle caps fit either injectors with a pin sticking out the injector end or 4 with more tiny
holes in the injector end. The following are listed at the Borg-Warner site ( http://www.borg-warner.com ) as being
resellers of Borg-Warner parts:

http://www.partsplus.com/ or http://www.autovalue.com/ or http://www.pepboys.com/ or http://www.federatedautoparts.com/

Most of the links above have store locators for find a store in your area.

Head gaskets
upper manifold gasket
lower manifold gasket set.
Exhaust manifold gasket set
Rocker cover gaskets - look for the rubber ones with the steel bushings - Summit has them
Short formed hose between thermostat hosing and intake manifold
6 ft 7/64" or 1/8" vacuum hose
2 ft 1/2" heater hose
1 1/2 ft 5/8" heater hose
Blue Silicone sealer
ARP antiseize or equal for the bolts
ARP thread sealer or Teflon pipe dope for the short bolts.
4 each 3/4" hose clamps (spare item in case the old ones are bad)
4 each 1/2" hose clamps (spare item)

Machine shop charges will vary - figure $275-$350 to have heads checked for cracks, cleaned, surfaced, valves ground,
valve guides reconditioned, valve springs checked and bad springs replaced.
 

nunly94gt

Founding Member
Feb 3, 2002
1,595
3
38
Mobile, Al
Mar 23, 2009
#5
  • Mar 23, 2009
  • #5
Damn man, I replace heads all the time on these 6.0L Diesels without that much trouble.
Im glad you wrote that up, I wouldnt have put sealant on the bolts and then had a huge problem.
I have access to all the workshop manuals, so thats not a problem. I work at a dealership and there all online even for an 88.
Thanks for the information!!!
 
You must log in or register to reply here.

Similar threads

9
Engine Donor '00 Mountaineer meet '91 Fox
  • 91firecracker
  • May 11, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
41
Views
720
Fox 5.0 Mustang Tech May 28, 2026
91firecracker
9
Engine Suggestions on an engine rebuild. Stock cam/GT40Ps or aftermarket on both for a fun weekend driver?
  • MadSquirrelTech
  • Apr 28, 2026
  • Fox 5.0 Mustang Tech
  • 2
Replies
23
Views
629
Fox 5.0 Mustang Tech May 7, 2026
MadSquirrelTech
Engine Explorer - Lower intake internal cleaning
  • R82148V
  • Nov 11, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
42
Views
1K
Fox 5.0 Mustang Tech Dec 6, 2025
rednotch
M
Gt40p headers
  • Mike3
  • Oct 14, 2025
  • 1994 - 1995 Specific Tech
Replies
13
Views
729
1994 - 1995 Specific Tech Nov 1, 2025
Blackhawkxx
B
97 GT with 03 explorer Eddie Bauer edition 4.6l
  • basbill73
  • May 10, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
2
Views
45
1996 - 2004 SN95 Mustang -General/Talk- May 11, 2026
squeak93
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?