351 GT40/Lightening lower - good price, not mine

[Gunnibronco]

http://forums.corral.net/forums/windsor ... ifold.html

[akaFrankCastle]

damn good price on that. Makes me wish I held out longer.

[Gunnibronco]

Patience grasshopper, patience.

A lesson I haven't learned.

I'm very impatient when it comes to guns and cars. Once the idea is in my head, the first "deal" that comes along is usually good enough.

Funny, current story, I've been pestering a guy in Syracuse, NY for a certain 1939 Plymouth part (via Craigslist). Today, he sold all his 39 Plymouth parts to someone else, locally.

Last night, we had the annual Gunnison Car Show "Main St Cruise". I ran into a 40 Plymouth's owner and discussed the parts I was missing. Today, he ended up giving my info to a local from Crested Butte with "enough parts to build 2, 1939 Plymouth Coupes". The CB local called me and I'm going up there tomorrow to check out his stash. I may buy the whole lot for a real good price. So tomorrow I may have enough 39 Plymouth parts to build 3 1939 Plymouth Coupes. Of course, I wanted to go up tonight, but he was busy.

I don't know if I'll build up a couple of these cars, or sell the parts I don't need. I'd probably come out ahead just selling off the parts I don't need, but one restored 39 Coupe and one bad a$$, hopped up, hot rodded 39 Coupe would make a pretty cool combo.

Patience grasshopper, patience.

[akaFrankCastle]

Yeah I know. I spent over a year hunting the best intake deal possible. I noticed things started drying up a little bit on the parts scene so I jumped when I saw one come up.

We need to talk Plymouths and the like some time. Perhaps in another thread or over on the HAMB.

[Gunnibronco]

I posted a build thread there. Love to talk more.
http://www.jalopyjournal.com/forum/show ... p?t=724191

[75DBE]

So I am confused. What is a 5.8L GT-40 Lower Intake Manifold? So the heads at GT-40 and the lower intake manifold is GT-40 as well? HUH?

[akaFrankCastle]

This intake gets the GT-40 moniker because the intake ports that match to the upper intake are the same size and configuration as the Explorer/Mustang GT-40 style. Essentially, each of those ports are offset from one another, forming a zig-zag if you drew a line through them. Flip over that upper you pulled the other day and you can see what I am talking about.

This is the only lower intake manifold, from the factory, that you can use on the 351W and use the GT-40 style upper with. Traditional truck (because that's what 99% of the vehicles were that Ford put the 351W in during the later years) featured an online configuration of intake ports. The upper intake manifold is also taller than the Explorer/GT-40, as the height (longer intake runners) is said to produce better torque through the range.

You can use a traditional truck lower intake manifold with a early EFI Mustang upper (also all intake ports in line, but shorter than the truck upper) but it requires the use of an adapter plate to do so. JD is running that configuration on his Bronco, now sealed in a time capsule. Also, Charlie, whom we met Saturday, has this set up on his motor as well. However, he is planning to swith to GT40 style.

As far as the heads go, I want to say the entire package of components were given the offiicial/unofficial designation as GT-40 when they were first introduced.

A Lightning truck, at least the early ones, featured 351W motors with speed density set ups, GT40 heads, and the 351W Lightning lower with GT40 upper. This is also pretty similar to the set up found in the 95 Cobra R Mustang.

[Gunnibronco]

Zach beat me to the punch.

There are GT40 heads, and intake manifolds. It was Ford factory high performance stuff.

There are at least 2 styles of GT40 upper intake manifolds, Explorer and tubular.

Both styles of GT40 upper manifolds bolt to GT40 lowers, the 5.0/302 uses one style GT40 lower used on some Mustangs & Explorers. The 5.8L/351 GT40 lower intake manifold is harder to find, they were only used on Lightening trucks, a 351W Mustang from the early 90's, and some 351W marine applications came with a cast iron GT40 lower intake.

GT40 heads will bolt to any 302 or 351W block basically. The early GT40 heads use stock style exhaust manifolds, the later 97-1/2 and up GT40 heads are referred to as "GT40P" heads and have different spark plug placement and require specifically built headers.

GT40 intakes will bolt to any 302 or 351W head basically.

You can mix and match componants. I have an Explorer GT40 upper and lower intake manifold bolted to my old 302 block & heads. They did happen to come off an Explorer with GT40 heads too.

[Colorado75bronc]

JD has gt40 tubular upper and a lightening lower

[Gunnibronco]

Here are the parts that make up a 351 truck lower, BC Broncos adapter, and Mustang upper-





Here is the 351 GT40 lower, you can see the difference in the shape of the intake runners. It is a very good performing piece of engineering.


Here is my 302 Explorer GT40 lower, it has the same intake runner shape/placement as the 351 intake, so it takes the same upper manifolds as the Explorers and Mustangs with GT40 lowers.

[Kinder]

So the GT40 uppers are the same for 302s & 351s?

[Gunnibronco]

So the GT40 uppers are the same for 302s & 351s?

Yes. Only the lower is different.