Would it be better if I got a stock truck intake manifold, upper and lower, and I port it out. Or would it be better if I get a mustang upper and lower or try to get a Gt-40 upper and lower for a good pricem, is it that hard ot get all the connections to work with these different style manifold ... the single blade TB, the fact that the throttle and cruise control cable will need to be shorter I am just wondering how hard this is. I think I heard that the truck intake makes good low end power, is this true. I gust got my air tools so I want to start hacking away at something! Not really, I want to do it right, but I want to know what is better for a "truck" engine. Also while I am at it, I am going to replace my valve covers with the Ford Racing ones, and throw on some 1.7RR. After I do this, I will probably go on the dyno so I can see if these mods helped.

 

I hear the gt40 upper & lower is the ticket, especially if you've never ported before.

 

The mustang and gt-40 manifolds probably have short, fat intake runners which will give you a lot of power at high rpm's. The truck manifolds have longer, skinnier runners for more low end torque. It depends on how you drive the truck. You might be better off just getting an aftermarket manifold. Edelbrock air gap manifolds are great for low end torque but i don't know if they make them for efi. I'm not sure you would see much of a gain from an intake change if you still have stock heads. What you would see is a change in the rpm of the power band.

-Jon

 

I suspect that the GT-40 isn't going to match the characteristics of your cam real well. All this stuff has to work together. I'd guess you'd be better off with the Edelbrock EFI truck manifold or a cleanup of the stock one. There's limits to what you can do to improve the stock manifold though if you're not going to port your heads to match. You do not want to open up the intake to head ports in the manifold without also opening them in the heads, the resulting reversion would kill your performance.

The best manifold in the world isn't going to do much as long as you've got stock heads. You might want to hit the swap meets and try to find a set of the "3-line" iron GT-40 heads. They can be had cheaply enough and would give you a real basis on which to build up the rest of the engine.

 

Good point StrangeRanger. The best intake in the world won't do much with the stock heads and cam combo. Probably about the best you could do with the stockers is the Explorer intakes, which make good torque but also flow good. Of course this means changing the throttle body and other crap as well.

The heads you are talking about are the GT-40Ps also from the later Explorers.

 

No, not the GT-40P heads, the old SVO GT-40 iron heads with the 3 line marking on the end of the casting. They're a glut on the market since all the 5.0 Mustang guys have switched to aluminum. I sold a low mileage fully-prepped set for $600, about half of what they cost me. There are better deals than that to be had too. Haunt the swap meets, you'll find them.

The GT-40P heads are very good too, but have that minor problem with spark plug angle, making headers a bit of a crapshoot. The GT-40s have no such problem. The Exploder manifold is fairly similar to the cast Cobra manifold and is probably more of a car manifold, as suits the application.

 

i believe those are original equipment on 93-95 lightnings. you can find them on the corral and on nloc.net

 

I never knew there were that many different versions of the heads. I knew they had the aluminum ones and the "P" ones, but thanks for the info. I am sure that some time down the line I will add those heads. As for right now, since I am going to get the Ford Racing valve covers and 1.7RR, I think I will just buy another stock upper manifold and port out the TB opening ot accept the BBK 56mm TB, and I will paint it black to match the valve covers. It will be cheap to do, and when I get something like an Edelbrock intake, I will just reuse the BBK TB.

 

You actually don't need to do any porting to install a 56mm throttle body. I had one on my truck and I know dvldog458 has a 56mm throttle body. It's not until you get up to the 61mm throttle body that you actually need to port the intake manifold. BTW, do you have mass air? If I were you, I would look at getting a larger air meter for your mass air before swapping to a larger throttle body. Most large mass air meters advetise roughly a 12 rwhp gain, and cost around $300. A 56mm throttle body will set you back about $285 and will give you a 5 hp gain @ 4500 rpm's on a basically stock engine. For the money, I'd go with a larger air meter. Just a suggestion

 

TF's right.
No porting needed for the BBK 56mm TB.
I'll be installing 61MM soon,and i'll try to post some pics of what i have to do.

 

i would have to agree, no need to port the 56mm. I have both the edelbrock upper and lower and the bbk/edel 56mm throttle body and noticed a heck of a horsepower increase. The rpms just jump at the touch of the throttle and with a k&n filter along with headers and a cat-back exhaust, I am keeping up and beatin up on some of my mustang 5.0 friends. Its really a great way to do it.

Next on the chopping block is my heads. I bought a set of gt-40's (not p's, spark plug problem with aftermarket headers) for $325 and have bigger valves in them with a valve job and all the extra's. Prob is I'm in college and dont have a nice money flow so they will have to sit. I cant wait to get the heads on with all the other stuff, my baby will fly!!

So my recomendation is to sit on the intake idea and get the edelbrock setup because all the mustangs uppers will give you a great deal of problems with intake tubes, throttle bodies, throttle linkage and all that fun stuff. Just stick to the stuff made for the f150. My friend with a 94 stang has the trick flow intake and there is no way on earth I would be able to put that thing in my truck!!! So there is my 2 cents.

 

I would love to put the edelbrock manifold and throttle body, however the upper/lower manifold is $529 and the TB is $299, that is way to much money for me to spend right now.

 

Strange Ranger,

My screw up on the head markings. I think the 40s are three line as you stated, and the 40Ps are 4 lines with the side marking.

Everything I have found does show the P to flow better than the standard GT 40s though. Header clearance is an issue for many, but if someone doesn't already have the headers then they do make a P specific header.

As for the intake I also agree, the Explorer is more a car intake. This leads me to belive that the P heads would make even better torque than they do in the Explorer if a stock truck intake was used. In stock trim the Explorer combo has more torque by a few lb ft (rated at 288 IIRC) but also makes more HP (215). This is with a mild cam.

I think with a still stock cam or a mild cam the P's with the truck intake would make for a good combo. It seems that the major high rev restriction in the trucks is more the heads than the intake IMO.


I've looked for this combo, but haven't found it with a stock cam. It seems that the torque retention may overcome the high rev HP increases with the other intakes. I did find a truck with the GT 40P crate engine from Central Coast that uses the stock truck intake with a FRPP cam, but with no comparison on intakes.

 

But the swap meets, at least around here, aren't **** deep in GT-40P heads. In terms of bang for the buck the older 40s are hard to beat

 

Beastie,

Don't know where you are pricing those items, but that's way too much to pay. I got my intake from Central Coast with my engine and they gave it to me for $459, Powered by Ford in Orlando, FL has them for $484 and the TB (56mm) for $234.95.

Mac's equal length shorty truck header works with the GT-40P head, that is what Central Coast sells with their engine combo for truck owners. #4 spark plug is the only one that gives you any grief and it isn’t that bad.

Although I agree with StrangeRanger about cheap GT-40's at the swaps, you can't beat a completely assembled set of GT-40P's new with a stick if you like to buy new stuff like me.

The exhaust port revision is what gives it excellent low speed flow values which equates to excellent torque down low where you need it in a truck. Remember, Ford revised them to help motivate a fat *** SUV so it would feel peppy. Brake specific fuel consumption (BSFC) is very low for these heads around .43 so they will get better fuel economy too since they are a bit more efficient in stock form.