gt40 intake

[Beamed]

so i wanna show my truck some love and get a gt40 intake. i like the tubular one but what vehicles did they come on. If i cant find a tubular one i want to know the next best choice over the stock 5.8 truck upper and lower. What vehicles to find them on at the junkyard. also what to port to free the flow if any is needed on the intake. thanks for the input

[jerg_064]

We'll it's going to be hard to pick up the GT40 lowers for a 5.8, as far as I know they only came on the 93-95 lightnings. There could be more, but nonetheless they're very rare and hard to come by.

All upper intakes have the same internal flow characteristics. Sure the tubular ones are nice and shiny, but they're also much more expensive and hold no performance gain over the cast. The cast uppers came on the 95ish-2001 explorers and some cobras(not sure what years). You should be able to find the cast uppers on ebay for around $100 as well.

Port matching the lower intake to the heads should help flow characteristics some and provide a small gain. If you can find them in the junkyard I'd go ahead and take the GT40 heads as well, they should be paired up on the cobra's and Explorers. The 5.8 should move enough air so that the GT40 heads won't hurt your low-end; they were on the lightnings. Even if you don't want to use the heads, if you could pull em for a cheap price you could turn around and sell them for a profit and maybe fund a cam swap.

[Conanski]

All the GT40 style intakes suffer similar choke points around the upper mounting bolts just behind the TB and in the lower runners on the end where they make an S turn. The Eddy Performer is a better design and the Professional Products Typhoon is an inexpensive copy. I'll agree the tubular GT40 certainly looks more trick that the others though.

[Beamed]

thanks for the input so what all would i nee to do to install the heads and intake on my truck, would i need new pushrods or lifters or anything thanks

[Terpfords]

you should be able to reuse your pushrods as long as the head has not been cut down to reduce combustion chamber volume.

[Conanski]

GT40 heads are a direct fit on the truck 5.8 after you bore out the head bolt holes to 1/2", use same pushrods and rockers. These heads are found on '96-'97 Explorer and '93-'95 Mustang Cobra. The '97-2000 Explorer got the GT40p heads which are slightly better performers but make headers a little more difficult to use.. less clearance on the spark plugs.

[jerg_064]

Originally Posted by Conanski

GT40 heads are a direct fit on the truck 5.8 after you bore out the head bolt holes to 1/2", use same pushrods and rockers. These heads are found on '96-'97 Explorer and '93-'95 Mustang Cobra. The '97-2000 Explorer got the GT40p heads which are slightly better performers but make headers a little more difficult to use.. less clearance on the spark plugs.

I thought the GT40s were only on the 95 to early '96 explorers and GT40Ps were '96-2001.(talking Explorer only here)

[Terpfords]

Not that long ago you used to be able to get the 5.8 lowerout of the FRPP catolog and guys used to sell their uppers when they went supercharged and wanted more rpm.

[jerg_064]

Originally Posted by Terpfords

Not that long ago you used to be able to get the 5.8 lowerout of the FRPP catolog and guys used to sell their uppers when they went supercharged and wanted more rpm.

I'm sure you can get a lower from FRPP; for a hefty price! As for the uppers; all and any gt40 uppers(cast or tubular) will fit on any lower. The lower is just wider on the 5.8 to accommodate the bigger block, but it still retains the same upper-lower mounting platform/design. And you can swap the uppers 180* so your TB can be on either the mustang(passenger) or truck(drivers) side.

[lew52]

Thats right you could buy Gt -40 heads & intakes from ford racing parts..Lew

[Conanski]

Originally Posted by jerg_064

I thought the GT40s were only on the 95 to early '96 explorers and GT40Ps were '96-2001.(talking Explorer only here)

Didn't think there was a 5.0 Explorer in '95?

[mxzx]

Is there a big performance gain with the GT40 intake over a standard truck intake on a 5.8?
Just to clarify, are the GT40 upper intakes the same (5.0/5.8)? 5.0 upper can be used on a 5.8 lower?

[Conanski]

As cast there won't be a hugh difference in performance between the GT40 and 5.8 truck intake, the GT40 lower may be a little better than the truck lower but the truck upper is less restrictive and has more throttlebody attached so it's probably a wash. The 5.8 and GT40 lowers are the two on the right, as you can see port size is fairly even, both intakes will benefit from port matching the lower to the heads and straightening of the ports at the corners.

[david00f150]

Would a 92-93 Thunderbird with a 5.0 HO have gt 40 intake and heads?

[Conanski]

No.. that's a HO motor just like what was installed in the Mustang, HO intake and E7TE heads.