GT40 tubular upper/lower intake manifold question

I wouldn't just swap the upper and lower without swaping the heads and cam. You can do it, but it won't give you any real horsepower with just the intake swapped. Buy it, and wait til you get the heads,,,,, scratch that if you can afford heads right now, do it all at once, then you'll really feel the power gain. There are lots of good heads out there: trickflow, edelbrock, afr's and explorer heads. Explorer heads will be the cheapest, but you need to change out the springs especially when you throw a cam in there and it wouldn't hurt get a valve job depending on miles and condition.

+1

an intake swap alone is good for 7 hp MAX, but it does look sweet. expect about 6 hrs in labor though

i did it ... so trust me.... ne1 who says they got 25 hp is lying or just doesn't know

and yes you should port it..... match it to the heads with a felpro 1250 gasket (the others are WAAAAY too big)

the lower is all that can get ported, and it has big enuff ports to support 450-500 hp as is, but velocity will be better if there are no "steps" so smooth the transitions from piece to piece.

also as far as heads... how big is your wallet ? at minimum.... get some iron gt40's and have the exhaust ported and polished... smooth the intakes and make it all fit good with a comp valve job to boot. the heads, + intake and head porting should run you about $700 total. you may need new valve springs over the stockers too depending on age. but... do those things and you will make a true 300 hp and run 12's on a 3200 lb car if it hooks

my buddy went 11.80's with less port work then i said, on a 125 shot and full weight '92 gt 5-speed on that same setup... iron 40's are no slouch, and i would never put box stock heads of any brand on a car. they ALL need exhaust porting, and some touching up.

a little $$$ goes a long way here

that was on et drags launching at 5k

the gt40 intake will flow more that the stock intake if you can gasket match it do it. I would get a 76 maf,headers and a bigger throttle body. Just swapping the intake will not add to much. do you have to run cats where you live? if not get an X pipe too YouTube - Fox mustang on the dyno

I would also make sure that it is a real GT-40 intake not an explorer intake that someone is selling as a GT-40.

Step 1: Get a 70mm TB and EGR spacer for it. You may have to open the mouth of the intake a teeeeeny tiny bit with a Dremel, but otherwise, it will match the 70mm TB very closely.

Step 2: Upgrade to a bigger MAF meter. 75-80mm would be ideal.

Step 3: If you're considering heads, you have to go all the way. At this point you're also looking at a good aftermarket cam, bigger fuel injectors, bigger fuel pump, and likely a tune to get the most out of it. Also, headers and an exhaust should be added, if you haven't done that already.

Low86GT said:

I would also make sure that it is a real GT-40 intake not an explorer intake that someone is selling as a GT-40.

Click to expand...

Tubular GT40=Cobra=Explorer. Anyone who tells you anything different doesn't know what they are talking about. They all use the same lower and will all perform within 2-3 hp on the dyno.

Now, as far as looks, well, that's something else entirely.