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

How to tell Gt40 vs Gt40p heads on explorer

  • Thread starter Thread starter Farmstad
  • Start date Start date Mar 11, 2023
Prev
  • 1
  • 2
  • 3
Next
First Prev 2 of 3 Next Last

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,967
4,080
183
Claremore, OK
Mar 14, 2023
#21
  • Mar 14, 2023
  • #21
You can swap the iheads, cam, and intakes and will not need a tune. The ECU will handle a mild HCI swap like that as well as a larger throttle body. If you need to move up to 24 or 30 lb/hr injectors then just get a calibrated MAF like a Pro-M or C&L.
 

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#22
  • Mar 14, 2023
  • #22
Is the Maf connected to injector size or is injector size calibrated into the computer? And I thought I would be able to get away with my 19lb injectors with a mild set up. Also I was thinking of getting the e303+ cam from summit racing with dual pattern cam.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,265
17,952
224
Massachusetts
Mar 14, 2023
#23
  • Mar 14, 2023
  • #23
Injector size of part of ECU calibration. The MAF outputs a known signal per unit of flow and the ECU calculates how much fuel to inject

The “calibrated MAF” was a workaround to alter the output signal so the ECU things it’s seeing more air than it actually is, so it reduced injector duty cycle, which is compensated by using larger injectors
 
Reactions: Farmstad

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#24
  • Mar 14, 2023
  • #24
Ok so if I pull a set of 24lb injectors from a tuck and then buy a 24lb mass airflow meter then it will for sure run fine with heads, intake and throttle body. As well as should be fine with a “computer friendly cam”. Also my last question before I am done is what is actually done during a dyno tune? I have heard from some people that it’s just only needed for wot and only adjusts timing and fuel pressure really. Thanks for all the help btw.
 

Attachments

  • A35387B2-0514-458A-804B-E569D2D8989D.webp
    28.1 KB · Views: 128

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,967
4,080
183
Claremore, OK
Mar 14, 2023
#25
  • Mar 14, 2023
  • #25
So you need to make sure and get the same type of injector that is already on your 94 which from the factory are EV1's. I believe these are some of the factory vehicles that came with 24 lb/hr injectors that will work:

92-97 F350 7.5L V8 (460 Big Block)
89-95 Taurus SHO 3.0L V6
93-98 Lincoln Mark VIII 4.6L
93 Cobra 5.0L
96-98 Cobra 4.6L

Getting the car in the hands of a good tuner and strapping it to a dyno should result in more hp and torque under the curve and better driveability. How much more hp and torque and how much better driveability depends on how far from stock the motor combination is. Car with HCI, cold air kit, and a good exhaust will gain from a dyno tune but you have to be the one to justify the cost of the chip and tuner's time which used to be $500 but I have no idea what is is now. My guess is you might gain another 20-30 hp with a tune on a mild 302 with a HCI swap.
 
Reactions: Farmstad

KRUISR

10 Year Member
Apr 16, 2015
1,822
929
143
Mar 14, 2023
#26
  • Mar 14, 2023
  • #26
As far as prices in Canada, I have sold "as pulled" GT40s for $400-500 as recent as two years ago (none more recently) and GT40Ps $300-400, again more than two years ago. On a side note, the first set of GT40s I pulled were on a '98 (probably dealer replacements due to warranty work).

Regarding your build combo, basically what I have in my 90 GT. A used stock short block, GT40s with smoothed intake and exhaust ports, upgraded valve springs (don't know which ones - previous owner), 1.7 pedestal RRs, untouched Explorer EGR intakes drilled and tapped for IAC in runner 5. 70mm BBK TB and EGR spacer - yes EGR is operational, 24 lb injectors pulled from a Navigator with eBay adapter plugs, 76mm C&L with flow tube of my own sizing. Cam is a Crower 15512. I was using factory air box with a K&N filter until I built my functional SVO style scooped hood and now get intake air through it.

I have a dual wideband and an Anderson PMS hooked up but not tuning anything yet, so far just monitoring. So only tuning to make run was the C&L and a good Base Idle Reset.

Where abouts in Canada are you?
 

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#27
  • Mar 14, 2023
  • #27
Ha I pulled the gt40 3bar at the junk yard from a 157000km engine for $88 so killer deal. Something like 180 some all including intake and throttle body. Good to know hopefully I can get my money back if I decide not to upgrade but more power from the 5.0 would be nice. Are you still running the stock fox computer rn or is the Anderson pms the computer? Why did you need adapters for the injectors by the way?
 
Last edited: Mar 20, 2023

KRUISR

10 Year Member
Apr 16, 2015
1,822
929
143
Mar 14, 2023
#28
  • Mar 14, 2023
  • #28
Anderson PMS is a piggy back tuner. It uses the stock ECU and plugs in between the ECU and engine. The adapters are to fit the different injector plug connector to the factory harness - EV1 style to EV6 style.

Nice score on the price. Five/six years ago around Ontario you could pull heads for about $40 a piece, now about $80-90 each. Intakes are about $35 (if you keep them bolted together you can sometimes get upper and lower for one intake price, otherwise they will ding you $35 each). I have typically sold EGR intakes for $150-175, but in the last year I have seen a few people asking $250-350 for Explorer intakes (not sure what they actually get).

I was running a modified Explorer 65mm TB for a while until I stumbled across a great deal on the 70mm. It is a great choice for a street cruiser - more than enough flow for a NA engine and obviously cheap to be had. Modification required is very easy if you can DIY things.
 

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#29
  • Mar 14, 2023
  • #29
@AeroCoupe thanks I will keep an eye out for those cars at a pick and pull. As for the calibrated maf I think it should work fine for my build with a small cam e303 or e303 plus and the heads and intake I have. Maybe even to be safe should I just do heads and intake when I have time and keep the stock h.o cam maybe that would be safer for the computer but I would have to take the entire engine apart again basically if I want to stick a cam in .
If I can have a car with more power for without taking it to a Tunner ( not like a small 10 15 20 Hp gain for all the work and money) and still have decent drivability and creature comforts that’s a big win. I have really figured out cars are a good way to spend lots of money so I like to ask to see how little money I can spend with out going down the rabbit hole lol.


Also was looking at a video for calibrated mafs on fox bodies.

Starting around 5:40 he says it’s bad because the computer is being fooled and the timing is more advanced with the placement on the chart which might not be good. But after he says if you going to a little change like 19 to 20 the change is not much and might be better with more timing. Anyways I am not entirely sure what I am asking and but don’t the 94 95 comptuters have different ways of calculating engine load or use engine load more often or something? You don’t have to watch that video or even answer this part but I thought I would ask and that’s what car forms are for right?
 

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#30
  • Mar 14, 2023
  • #30
Yea @KRUISR they charged me for the upper and lower separate ): me and my buddy had 5 min to pack stuff up and get out of the salvage yard but if we had time we would have bolted them together. 65 mm is stock explorer size right and GT is like 55mm stock? You tried running your car yet or just have it back together rn?
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,967
4,080
183
Claremore, OK
Mar 14, 2023
#31
  • Mar 14, 2023
  • #31
The real difference between the 87-93 and the 94/95 cars is the OBD-I and OBD-II. The ECU in the 94/95 will handle the HCI, TB, and MAF change with no issue.

I ran a Pro-M 70mm Bullet calibrated for 24 lb injectors for 5 years with zero issues and hundreds (more like thousands) of other guys have done the same. Your call.
 

KRUISR

10 Year Member
Apr 16, 2015
1,822
929
143
Mar 14, 2023
#32
  • Mar 14, 2023
  • #32
Stock foxbody TB is 60mm, stock MAF is 55mm.

I put my car on the road in 2017 with stock long block and cam, 1.7RR, Explorer intakes and 19lb injectors and a 73mm C&L and full 2.5" catted exhaust. The following year I swapped in the engine I described above still with the Explorer 19lb injectors and same exhaust. The following year I added the dual wideband and connected the PMS, 24lbs injectors and 76mm MAF. COVID hit and I focused on 5 lug swap, manual trans conversion, big brake swap and custom hood/ram air. This year the plan/hope is to get big rear brake swap finished, touch up some paint, finish fabricating, paint and install my custom shaker hood set up.

The project is never done, just evolves to the next stage.
 
Reactions: Farmstad

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#33
  • Mar 14, 2023
  • #33
I trust it that is why the h/c/I swap is so common. Also the 94-95 computers are still obd-I it’s different than the fox a9l thought. The had obd-II in the v6s and the 96 and up Gt when they went to the 4.6. I think like you said for what I am doing I should have no problems but I am still weary of what everyone says about he 94-95 computers being finicky. Won’t do the swap too soon but thought I would ask about things before hand.
 

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#34
  • Mar 14, 2023
  • #34
Oh I really like that you went with the manual swap makes driving so much more fun. So glad I got a 5 speed mustang as my first car. And I bet the five lug is nice being able to run more rims and have rear disk breaks. Also when you still had the 19lb injectors did you have the cam in it as well on stock tune? And that’s so true that a project is never finished. I had a perfectly fine rear end in my car that being the 7.5 open v6 mustang diff but I decided that it wasn’t good enough and that I needed to get an lsd installed and that turns into well I should do control arms as well and shocks and rebuild the track lock… just so it handles minimally better and can do two wheel burn outs…
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,967
4,080
183
Claremore, OK
Mar 14, 2023
#35
  • Mar 14, 2023
  • #35
Learned something new. I know the 94/95 GT’s and Cobras have the OBD-II ports just didn’t know they were not used.
 

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#36
  • Mar 14, 2023
  • #36
Yea the have the port for obd-II from factory but doesn’t work. You have to read codes from a plug up by the top left of the engine bay.
 

KRUISR

10 Year Member
Apr 16, 2015
1,822
929
143
Mar 14, 2023
#37
  • Mar 14, 2023
  • #37
Oh my car hit the street in 2017 with 4 wheel discs, 4 lug, based on a modified Lincoln LS set up (rotors and calipers redrilled for 4 lug) with 2001 spindles.



I had the Explorer 19s on the engine combo above with the dual wideband and PMS hooked up. It ran great and the only reason I swapped to 24s was when I would "get into it" and rev it up and power shift my AOD at 5500 rpm the PMS showed my injector duty cycle was hitting 95+%. AFRs on the wideband were fine in the low 13, high 12 range, but I decided to go up a size just to be safe.

How she sits now...

 

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#38
  • Mar 14, 2023
  • #38
That’s a good looking car I love the dark purple paint. Would have got a foxbody if they weren’t so expensive. My car looks 10x worse ha was sitting outside in a gravel storage lot for years because of it was a v6 with a blown head gasket but becuase of that it had low km good bushings and was for real cheap. That’s it but my friends v6 Camaro.

Got an aftermarket cobra style bumper I found at pick and pull that I plan on painting and putting on the car later
 

Attachments

  • D7AFD381-6D52-4A0C-9252-2362D9E811BF.webp
    835.8 KB · Views: 222
  • A733D7F0-7663-480D-B94B-A87544D0B5D5.webp
    806.7 KB · Views: 131
  • 8D0088BF-3A35-4587-ABA7-949176185E81.webp
    226.7 KB · Views: 122

KRUISR

10 Year Member
Apr 16, 2015
1,822
929
143
Mar 14, 2023
#39
  • Mar 14, 2023
  • #39
Nice start. I like the cobra bumper idea too.

Here is what mine started as in 2015 when I bought it.



I paid $1500 for a 90% complete car that was disassembled. Factory black on black loaded automatic car.

I modded chassis and suspension as I put it back together.
 
Reactions: Farmstad

Farmstad

Member
Jun 30, 2021
60
13
18
Canada
Mar 14, 2023
#40
  • Mar 14, 2023
  • #40
wow has come a long way hasn’t it. Probably a nice payoff seeing how it was to what it is like now. Do you have lowing springs or coil overs on it now?
 
Prev
  • 1
  • 2
  • 3
Next
First Prev 2 of 3 Next Last
You must log in or register to reply here.

Similar threads

M
How To Decode
  • Malcoll1
  • Mar 10, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
7
Views
289
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Mar 10, 2026
FoxChasis
F
Engine Catch Can or not?
  • R82148V
  • Mar 4, 2026
  • Fox 5.0 Mustang Tech
Replies
9
Views
366
Fox 5.0 Mustang Tech Mar 6, 2026
ctandc
C
9
Engine Donor '00 Mountaineer meet '91 Fox
  • 91firecracker
  • May 11, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
41
Views
935
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
863
Fox 5.0 Mustang Tech May 7, 2026
MadSquirrelTech
1
Engine Motor swap from a 2003 Explorer
  • 1996mustang new
  • Oct 9, 2025
  • SN95 4.6L Mustang Tech
Replies
7
Views
621
SN95 4.6L Mustang Tech Oct 16, 2025
squeak93
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
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?