Freaky's Official Explorer and GT-40 intake thread. 56k, dont' bother

Discussion in 'Fox 5.0 Mustang Tech' started by Stang89LXCPE, Jun 3, 2005.

  1. ok, this thread is designed to inform the the average mustang guru of the wonderful similarities and diffences between the GT-40 and 2 types of explorer intakes as well as the heads that came on them. I will continue to add information as I feel it is needed, or pictures to help. I will refer to the intakes as explorer 1 and explorer 2 from here on out. EXP 1 is the early 95-early 97 intake and the EXP 2 is the 97 and later. This is not an install thread. If you need help installing the intake, click here

    All Explorer motors from build dates late 95 (last three months possibly four), all of 96, and the first two months of 97 come equiped with Cast iron GT-40 heads. They are the same that were on the 93-95 cobra and the 93-95 lightnings. They have 3 verticle bars on the front face of the head. These are not the "P" heads. The P heads were used from march on in 97 up to 00 or 01, whenever they quit installing 5 liters in the explorers and mountainers. The "P" heads will have 4 verticle casting bars on the front face of the heads. (front and rear corners, where the accessory bolt holes are).

    Now for the intakes....
    Ford had such success with the GT-40 on the mustangs, that they found a way to build a cheaper (for them) copy of the tubular. and the casting of the "Explorer" or Mountaineer" intake was born.

    here is a pic of the stock 86-95 style lower
    [​IMG] And here is a pic of the basic GT-40 lower

    The Real GT-40 topside view [​IMG]
    underside view [​IMG]

    the three uppers from left to right GT-40, 96 explorer, 97^ explorer. Notice the similarities on the inlet tube, and the actual shape. The explorer is just an uglyier looking casting of the tubular GT-40 [​IMG]

    the three lowers from left to right are 97^, Real GT-40, and 96 explorer. Notice the intake on the left with no EGT hole on the upper flange mounting area. Also notice the #5 intake runner with no casting for the ACT hole [​IMG]

    EXP 1 had the Same production dates....late 95, all 96, and the first two months of 97 (JAN and FEB) use the intake that is setup to run internal EGR. (NOTE= all explorers had EXTERNAL EGR, but the first go round had the provisions for internal, as they were "leftovers" from the cobra line. There will be a sticker on the intake somewhere around the throttle body inlet that will have the part number, build date and location. Every intake i have had has still had this sticker on it. EXP 2 will be from 3/97 and later

    You are going to want this intake (exp 1)if you have to pass any kind of emissions testing. This intake also has a boss in the #5 intake runner for the ACT sensor (air charge temp sensor). It will need drilled and tapped to a 3/8 NPT (national pipe thread). Also at the back of the intake, there is a boss that will need drilled for the coolant supply to the EGR space on the throttle body.
    EXP 1#5 intake runner [​IMG]
    gt-40 #5 intake runner [​IMG]

    pic of underside of exp1 and exp2. exp 2 is on the left (non egr) and exp 1 is on the right (egr)

    Now, the later 97 and on intake does not have the provisions for the internal EGR. Also, there is no boss int the #5 intake runner for the ACT. I have drilled and tapped these before, but the intake runner itself is very thin and there are not too many threads to hold the sensor in. You can either drill and tap the intake runner for the ACT, or relocate it to the air inlet piping for better temp readings. Also, in the rear passenger side where it would need to be drilled for the EGR spacer coolant line, there isn't as much material there.
    [​IMG]EXP 2 #5 runner

    The early intake 95-96 also has a thicker flange area on the upper ( around the bolt holes that bolt it to the lower). they are about twice as thick as the later intakes. the later intakes (upper) crack quite easily (both ears of the upper on mine have been broke and rewelded. Does not affect performance, but isn't the prettiest. EXP 1 on the left and the later EXP 2 on the right
    [​IMG] [​IMG]

    The later intakes 97^ are easier to find on ebay and in the salvage yards, but are not the better intake. If you are buying one on Ebay, the earlier one will bring more money. Also remember that the later intake will not work with the EGR system and probably won't pass an echeck without it. (I honestly don't know if it will pass or not, as I do not have emissions testing where I live).


    Now to sum it all up, the early lower intake is the exact same part number as the lower from the GT-40 aftermarket intake. The upper is a casting of the tubular aftermarket. Where I live, They don't ususally sell the intake and heads seperately unless the motor is damaged, and at the point, you may not want the heads. Some yards will sell you the intake and heads. If they won't, check prices on the entire motor for a 1996 Explorer. Any reputable yard will ask the date. tell them 12/95 or 1/96. Keep it early. There have been some cases where ford mis matched parts like P heads with the EGR intake. I know I've priced a couple around here with 120K miles for about 400-500. At that price you get the intake, heads (GT-40's), and the throttle body. Then you can either sell the shortblock to recoupe some dollars or keep it for a spare. casting numbers for the GT-40 and EXP 1 lower are "RF-F87E-9K461-BA. The EXP 2 casting number is
    RF-F87E-9K461-BB. gotta watch as they are almost the same, but only the last two letters changing.

    The Explorers and Mountaineers came with a 65MM Throttle body. This will require a little work, but not much (not enought to justify spending 150+on a BBK one!)

    The linkage arm on the explorer is too short to work with the mustang cable, so, if you have no use for your stock throttle body...Carefully remove the likage arm from the mustang unit and remove the explorer arm. The mustang arm should fit in the same hole. I took a drill and drilled (not too deep) a pilot hole in the ceter pivot pin (where the lever connects)for a 1/4-20 tap. I Tapped it and installed a short bolt (1/2" long) with a lock washer and a flat washer to secure the new arm. I will add some how to pics later
  2. Nice work...always wondered about the differences.
  3. Nice write up! :nice:
  4. awesome. Thanks for going thru the trouble. Something everyone should at least glance at. I run a 600 carb so it's no biggie, but my next 5.0 will prolly be EFI so that information is really good to have. Thanks
  5. Yeah that is great, See I'm learning more about this stuff every day!
  6. I will also add that the 93 Cobra lower is the same lower as the GT-40. The 94-95 Cobra lowers are the same as the 93, but the boss in the #5 intake runner isn't drilled and tapped.
  7. Stang89 - great write up and pictures!

    One question -- are you certain on your reference to "Jan/Feb 97" build dates? I would imagine the first 2 months of production for 97 model year Explorers would actually be Sept/Oct of 1996. Recall the plant turn arounds/re-tools are usually in August, and it's sometime in Septemeber that they usually start building the next model year vehicles.

    That's all I can add to your excellent summary.
  8. 100% positive, no. i do have a pic of the build tag for this EXP1 intake. it was 1/24/97. Unfortuneatley I didn't get to remove it off of the explorer myself. of all the reserch i've done, it was at the end of febuary when the switch was made, although there have been a bunch of cross breeds (P heads with EGR intake) etc. Just depended on where they were built and what they had left in the parts bins.
  9. My guess is then that it was actually the first 4-6 months of 97 production that had them then (Sept. 96 - Feb. 97).

    I had read in another source that it was only the first two months of 97 production - which would have actually occurred in 96.
  10. I would guess that it woul be the first 4-6 months of production, as the first two months in 97 have to be included. As this one was of the early design and had the 1/24/97 date sticker on it. I'm working on uploading the pic now. Maybe that will help.

  11. Thanks for posting that. Definitely a nice writeup.
  12. here is the pic Michael
  13. I recently built a purposely mild 351 Lightning for a 4,000 car w/lots of hiway miles & 3:55's. Wanted lots of mid range. Found a GT40-351 lower that I mated with an early explorer upper, did a little
    port matching between the upper and lower. Has great mid range with a 210/477 cam
    even with the bigger motor, and still gets 22 mpg!
  14. Thanks for going through all the trouble to share this great info! :nice:
  15. I think this is as good a post as any to be nominated for a sticky. I know for a fact Ill be using this info as a guideline for when I go to the junkyard. Good write up.
  16. Great write-up! This should be stickied or saved or something......
  17. Do you have the different weights?
  18. great info thanks :nice:
  19. of interest, my 97 explorer motor has the gt40p heads, but came with the early intake WITH the egr stuff. They must have used the leftover early intake style late into the 97 model year.
  20. great into thankx