The GT40 was the tubular upper intake and the lower which is shared with the Explorer and C@obra intakes.

 

A true GT40 intake is the tubular one sold through SVO, but the cobra and Explorer intakes are commonly called GT40s. Ford stopped making the tubular version because it was costly to produce and was known for cracking. The three of them all share the same lower manifold which has round/staggered ports as opposed to the stock intake's oval/inline ports. Flow numbers between the three are very similiar from charts I've seen.

Jim.

 

The reason for discussion of upper and lower Gt 40 intakes: there are different versions of the lower intake for 302s and 351s. Both use the same upper intake. Also, there were some upper intakes (93 Cobra, aftermarket box intakes) that used a GT40 lower.

IMHO, there are many intakes available now that are superior to the GT40, so unless you already have one or find one for cheap, I'd use something else. I will admit, they did look cool.

Likewise, 93 Cobra and Explorer intakes are really not that good compared to Trick Flow or Edelbrock.

Pete

 

The '93 & '94-'95 Cobra intakes, as well as the GT40, flow ~11-12% more than the Explorer on average.

Here are some flow numbers from Edelbrock's testing. The first 8 numbers are each runner, the bold number is the average.

Runner CFM
Intake 1 2 3 4 5 6 7 8, Average

Stock 5.0: 123 140 142 145 119 139 133 150 136

GT-40: 186 202 202 204 182 197 198 201 197

'93 Cobra: 187 203 200 200 188 206 207 208 200

'94-'95 Cobra: 184 200 197 198 186 206 206 207 198

Explorer: 169 180 176 180 177 177 183 183 178

The Explorer intake is often touted as being equal to the GT40 and Cobra units however the numbers say otherwise. That said, whether you'd feel much "seat of the pants" difference is debateable.


Jeff

 

Tubular GT-40

If you can find for cheap, and want to use a "tubular" GT-40 manifold, make sure it has the larger baffle on the bottom . . . short version wil eat oil quickly because it "floods" the PCV.

Get the larger baffle model or repair it with the larger baffle and then no issues.

They are the coolest looking manifold out there . . .

HTH

Doc :beerchug:

 

Here is a picture of my GT40 intake assembly.