question about gt-40 heads
01-12-2012, 02:08 PM
#1
2nd Gear Member
Thread Starter
Join Date: Oct 2011
Location: New Hampshire
Posts: 354
question about gt-40 heads
i bought my 90 GT not too long ago and the guy i bought the car from didnt know too much about it because he got it from someone that just needed money quick...he wasnt really a mustang guy, just buys and sells cars on the side. So long story short...he was told it had gt-40 heads in it. How can i tell if they really are? Is there a number or anything on them? If they are not i want to put a pair in. Thanks!!!
01-27-2012, 10:02 PM
#9
D.R. THE PATHETIC DORK
Join Date: Jun 2007
Location: West Virginia
Posts: 30,863
01-28-2012, 06:36 AM
#10
4th Gear Member
Join Date: Oct 2009
Location: Pennsylvania
Posts: 1,772
Here you go, 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.
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
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
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
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.
Here is a pic of the build sticker that was on this early 97 (EXP 1)
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.
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.
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
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.
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
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
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
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.
Here is a pic of the build sticker that was on this early 97 (EXP 1)
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.
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.
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
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.