GT49 Clarity

[buknbronco]

Sorry if this seems like a dumb question, but could someone explain a little more about gt40 heads and intakes. Did they come on 5.0's or 5.4's? Either way does the lower intake from a GT40 work on a 5.0/302 without the GT40 heads?
Thanks

[Delta 4 Wheel]

the 4.6 and 5.4 motors are no longer the Windsor type motors, but Modular and nothing will fit in the intake system.

Gt-40 intake lowers have round intake ports and are a higher flowing intake than the stock square port mustang ones. They need to have one of the 3 upper intakes to work. 1. Ford Explorer 5.0 2. 1993 Cobra 3. Gt-40 tubular, listed in order of flow rates, less to more.

The Gt-40 heads are a better flowing head than a stock stang, but not nearly as good as an off of the shelf edelbrock, AFR, Trick flow etc unless radically ported and valves punched out to a larger size. They are a good bolt on for lower end mild builds, and will work very well on our rigs because of the smaller intake runners which will increase velosity and low end torque. With some new larger valves, you will be in a good range for a nice 302 or a mild 347 build however, withe the cost associated with doing this you would be way better off getting a set od edelbrock heads. They are a cast iron head, unless you get the gt-40X which are aluminum. The Gt-40P heads came on the Explorer 5.0 ONLY and do out flow the gt-40's by a small margin but not nearly enough for us to notice. They are the only Windsor head that changed the spark plug location since the 260 CI SBF motors of the 60's. The plug comes in pointed at the piston top instead of at the angle you are used to seeing. This is suppose to increase combustion effenciency. These heads have header fitment issues, however, I have found that with a 45 degree boot some non-P head headers will fit like the Duff headers (L&L) and I am sure the JBA's would fit as well. THese heads came on the 1997-1998 exploder, the 1996-97 Exploders had the gt-40 cobra heads.

Both heads will work with a stock intake set up, but due to the miss match intake ports, you may lose some flow at high RPMS. With a 1250 gasket, and and any aluminum lower intake, you will be pretty close to port matched and will be fine. Light port matching can be done pretty easilly. Keep in mind, any of the above heads with 2.02 intake valves will NOT work with stock pistons unless the pistons have been fly cut. the Gt-40 heads have 1.84 intakes and will bolt right on. The P heads have a 58CC Chamber, and the regular 40 heads have 60 cc chambers.

hope this helps

[crawlin68]

What he ^ said! Except the Mustang intake ports are oval, not square.

[buknbronco]

Thanks for the info.
If I have a 92? 5.0 intake right now, would it be worth it to go to the GT40 lower and ? upper now? I have a slighltly larger cam shaft(still talking about the bronco motor ) right now, and want to try and do as little engine mods as possible?

Thanks
Wes

[Delta 4 Wheel]

What he ^ said! Except the Mustang intake ports are oval, not square.

You know I have never seen one in person. I was thinking of the Holley square port for some reason...

[Delta 4 Wheel]

Thanks for the info.
If I have a 92? 5.0 intake right now, would it be worth it to go to the GT40 lower and ? upper now? I have a slighltly larger cam shaft(still talking about the bronco motor ) right now, and want to try and do as little engine mods as possible?

Thanks
Wes

The stock stuff will support your needs just fine.