Gt40 Upper/lower On Stock 302 Ho

DM87GT said:

Were you running the stock E7 heads and HO cam with the Cobra intake and got these improvements in the quarter? That is very impressive with just the intake and TB change! People on here tell me I'm wasting my time putting my GT40 intake on my stock HO 302! Basically, I am doing what you did by installing the Gt40 upper and lower and a new 70mm TB from Summit Racing. All the other mods to the engine from delete pulleys to the BBK shorties and the new TCI Street/Street C4 with 3000 stall with the intake and TB change should wake up my Mustang. I just want the motor to breathe since the stock intake is choking the performance!

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yes, stock E7 heads and stock HO cam. The intake is pretty easy to change, it's worth a shot IMO. I'm no outlier, and no hardcore dragstrip junkie, it just plain worked. Back in the day there were several of us who were able call bull on all the theoretical naysayers because we had been there and done that and had huge timeslip improvements to show for it.

This is old but I ran into this. I found an upper and lower gt40 intake with the EGR for 200 new in the box guy needs the money and already sold the car my 88 is stock other than bbk shorty heads h pipe magnaflos pro series dumps. Maf conversion underdrive pulley cai just bottom line mods. This is my first project car. Is it worth the buy? I plan on getting a 70 mm tb as well. What els will I need to make this intake work in my favor

88mustang on a budget said:

This is old but I ran into this. I found an upper and lower gt40 intake with the EGR for 200 new in the box guy needs the money and already sold the car my 88 is stock other than bbk shorty heads h pipe magnaflos pro series dumps. Maf conversion underdrive pulley cai just bottom line mods. This is my first project car. Is it worth the buy? I plan on getting a 70 mm tb as well. What els will I need to make this intake work in my favor

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welcome...

start your own thread vs. hijacking an old one- you will get more responses. That being said, post a picture of the "gt40" manifold. I see too many guys selling explorer manifolds off to newbs as real gt40 ones. What else is done to your car?

Mustang5L5 said:

New in the box? What kind of intake is this?

If it's an explorer intake, it's $100 too much.

If it's a real GT40 intake...it's $400 underpriced. Buy it and resell it on Ebay

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That was my thought, but is there really such as thing as a NIB explorer intake? Can't picture anyone ever going to the dealer and asking for one.
My guess would be it's a Chinese cobra.
If it's a real tubular, i'd buy it and put it on the car.
Wish I never got rid of mine even though I have nothing to use it on. That intake was a thing of beauty.

I paid $150 for a TMoss ported Exlporer intake, 70MM TB and spacer, fuel rails and 19lb injectors 3 years ago. The jy are loaded with these intakes. I'd never pay over $75 for one and agree with passing on the Chinese made Cobra.. The explorer intake flows just as well as the $500 GT40 one..

My advice is to get a jy explorer intake- tap the #5 runner for the IAT and if you want to step it up a notch, have the lower sent to Tom Moss for porting. Grab the hard coolant lines too as they are different than the mustang ones.

STill waiting for the OP to post a pic of the NIB intake.

When you do the intake swap, here's some help...

Explorer intake swap.

The ACT (Air Charge Temp) sensor will probably need to be moved. The GT 40 lower manifold isn't drilled & tapped for it to go into the intake like the stock manifold was. There is a boss cast into the GT 40, but a machine shop will have to drill & tap the new manifold. The best spot for the ACT is the air box if you don't do the drill and tap thing. You get to cut and splice the 2 ACT wires in order to make them long enough to reach the air box. Solder the wire extensions on the existing wires & use heat shrink tubing to cover the splices. Offset the place where you cut the wires so that you don't have a big bulge when you put heat shrink over the 2 wires to cover & protect them. The air box gets a hole (5/8" or so) for the ACT drilled about 1 1/4" down & 1/1/4" in on the front top side near the upper radiator hose. A brass fitting nut from Home Depot or Ace Hardware secures the ACT into the air box.

If you are very clever, you will find that the ACT connector comes apart so that you can remove the pins. A very small screwdriver releases the lock in the front of the center insert, while another small screwdriver inserted in the back pushes it out. Once the center insert is out of the connector shell, the pins come out easily. New pins are available from AutoZone in a $5 electrical pin kit for Fords. Crimping the pins on the extender wires saves you from having to splice them twice: once to put the connector on and once to extend the wires.

6 ft black 18 gauge wire
6 ft green 18 gauge wire
6 ft 1/4" heat shrink tubing
1 ft 3/16" heat shrink tubing

Measure the 2 extender wires & cut them to length, crimp one set of pins on them. Then mate up the extender pins with the wiring harness & slide the 3/16" heat shrink tubing over them & shrink the tubing. Then slide the 1/4" heat shrink tubing over the pair of wires and shrink the tubing. When you are done you'll have about 1" of wire left without heat shrink tubing on it to strip & crimp the new pins on. Stick the new pins in the old connector shell, assemble it and you are done. It looks as good as factory. Some wire loom can be used to enhance the "Factory Look".





Use the TPS and IAB from your old throttle body. All the EGR passages were there and fit OK. Use you old fuel rails and regulator. You will probably need a new EGR spacer adapter and gaskets. Without the EGR spacer, there is no place to mount the throttle linkage support bracket.

I used the stock water lines on the Explorer manifold and they connected up to the EGR without any problems. I made a “U” out of ½” copper pipe and sweat soldered it together. Then I used it and some hose with clamps to bypass the leaky heater.

The vacuum lines you need are 1 small line for fuel pressure regulator, 1 small line for A/C,1 small line for EGR and another small line for the smog pump. One big line at the back goes to the vacuum tree for the power brake & A/C, one big line goes to the PVC valve. The other big line goes out the front for the carbon canister. In a pinch, one of the small lines can connect to the spare port on the vacuum tree. Cap or plug the remaining lines since they aren't needed.

The stock Explorer linkage didn't come anywhere near fitting, so I made an adapter plate for the throttle linkage so I could use the 65 MM throttle body.

This is what I did:
Make a drawing of the position of the old throttle body linkage arm and its angular position relative to the centerline of the throttle body. Remove the ball stud off the explorer TB to make way for the adapter plate. Drill and tap a 10-32 hole in the linkage parallel to the TB shaft. Make an angle bracket out of 1" angle iron 3/8", drill a 3/16” hole in the center of each one of the legs. Then bolt it on where the hole was drilled & tapped. Then make a circular adapter plate out of 1/4" thick aluminum to bolt the two linkage arms together. Then bolt the aluminum plate to the existing linkage, and the angle bracket. Next mount the arm with the ball stud off the old throttle body on the adapter plate using the drawing to get the angle correct. You will need an aircraft type countersink for one of the bolts that secures the plate to the explorer linkage arm. It ends up being under the arm with the ball stud for the linkage. It works great and looks neat.

The Explorer TB could have been real simple if I had a gas welding torch or taken the TB to a welding shop. Just grind the mushroomed part of the TB shafts so that you can pry the linkage arms off. Then swap the stock arm onto the Explorer TB and braze it onto the shaft. It Takes about 3 minutes or less worth of work with the torch, so it shouldn't cost much.

I didn't have access to a welder, so I fabb'ed the plate in my shop. I took about 1.5 hours to do it, it was a measure, cut, and fit type of operation.

Also see http://www.veryuseful.com/mustang/tech/engine/ConvertingExplorer65mmTB.pdf for modifications to adapt the 65 MM Explorer TB to a Mustang

Vacuum line connections:
One large vacuum line from the upper front goes to the carbon canister

One large vacuum line from the rear goes to the vacuum tree.

One small line in the front feeds the Smog pump solenoid control valves on the rear of the passenger side wheel well..

One small line in the rear goes to the fuel pressure regulator.

One small line in the rear goes to the EGR suction regulator.

One large line in the rear goes to the PVC valve.

Diagram courtesy of Tmoss & Stang&2birds - Typical Vacuum Routing for a Fox stang 5.0:

Diagram courtesy of Tmoss & Stang&2birds - Intake manifold bolt tightening sequence for a 5.0 Fox stang:


Intake manifold to head bolts
--Step 1 96 in/lbs
--Step 2 16ft/lbs
--Step 3 23-25 ft/lbs

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Here's some tips...

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. Look in the A/C repair section for the fuel line tools. They look like little plastic top hats. You will need the 1/2" & 5/8" ones. The hat shaped section goes on facing the large part of the coupling. Then you press hard on the brim until it forces the sleeve into the coupling and releases the spring. You may need someone to pull on the line while you press on the coupling. Put some motor oil on them when you put the line back together.

The A/C Compressor comes off with lines still connected. Mark all the electrical, smog and vacuum lines with tags to help you remember where to re-connect them. If you have a digital camera, take several pictures.

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. Put some cardboard in the lifter valley to help catch the gasket scrapings. Have a shop vacuum handy to suck up the scrapings and any coolant that leaked into the lifter valley.
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.

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. Put an alignment mark on the distributor base and the engine block. 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. Now you can pull the distributor out. Be sure to put a rag or cap in the block where you removed the distributor. It will save you trouble if something falls into the empty distributor hole.


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. Also use the weather strip adhesive on the side of the gasket that mates to the head. When you are done, the head surface and the gasket surface that mate together will have weather strip adhesive on them. 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. TADA! no leaks, and no gaskets that shifted out of place.

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 $3-$4 per kit. 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.

Use motor oil on the O rings when you re-assemble them & everything will slide into place. The gasoline will wash away any excess oil that gets in the wrong places and it will burn up in the combustion chamber. Heat the pintle caps in boiling water to soften them to make them easier to install.

Plan on doing an oil change within 2 hours of run time on the engine. This will get the debris and coolant out of the oil pan.

Consumable items:
Upper manifold gasket
Fel Pro 1250 or equal lower manifold gasket set.
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
4 each 3/4" hose clamps (spare item in case the old ones are bad)
4 each 1/2" hose clamps (spare item)

What can happen if you don’t use the stay in place gasket…

Ask Nicoleb3x3 about the intake gasket that slipped out of place and caused idle and vacuum leak problems that could not be seen or found by external examination. Spay everything with anything you have, and you won't find the leak...


Want to wear yourself out with info on the Explorer intake manifolds? See http://www.stangnet.com/mustang-for...d-gt-40-intake-thread-56k-dont-bother.551505/