351 EFI Intake questions

[RedLeg0811]

Hi All,

I am in the process of getting my EFI items together for my 351w. I know many people have gone with the 351 truck lower BCB adapter and 5.0 upper.
The 351w is bored over .030 and has Edelbrock heads, mild cam.

Talking with a friend at work that has worked in a speed shop, is a Mustang guy, and works on the calibration of our Semi trucks, he said that the stock 5.0 intake is one of the first things that the mustang guys replace because the air flow is restrictive on a 5.0.

Another friend who builds engines, but is an old school carb guy was surmising that since we want the power in the lower RPM range the stock 5.0 would be alright until you hit higher RPM and then you would loose power. He though for most of the stuff we do in the bronco it would work fine.

Guess I am just wondering how much the stock upper will affect performance.



My other option is aftermarket which bumps up the price a lot. I could go with the 5.0 upper for now and sell it down the road...

 

[SteveL]

The lightning lowers are popular if you can find one

 

[70_Steve]

I don't remember reading of anyone on this forum who has done an actual dyno comparison of the truck lower/adapter/5.0 upper vs some other manifold configuration. Most of what I read is supposition or, at best, seat-of-the-pants experience. But people use the truck lower/adapter/5.0 upper because it's the cheapest manifold combination when going EFI.

Besides aftermarket, there is still the GT40/Lightning lower and GT40 or Explorer upper, which is what I run. But I have no idea what those GT40 lower manifolds go for now.

 

[hankjr]

the truck lower, adapter etc route is a tall assembly. depending on body lift and hood configuration, you might be ok, but if not, you would run into hood interference. the lighting lower buys some clearance but are not so quick to find and spendy. I have no data on flow differences.

Hank

 

[Timmy390]

I'm running the GT-40 lower and upper and even with a 1 BL, scoop was the only option and I had to modify the hood bracing. I would take a 3 ich or more BL to clear. The main issue the TPS sticks up high. Price for a lower is $350 and up for a cast iron boat version(I'm running that) and the price goes up from there for an aluminum version. Seem them listed for $600-800

I can see how the BC adapter could be a bit restrictive but you will not get that till the upper RPM band. My 351W make max HP at 3800 rpm's if i remember right.

The truck lower, BC adapter and Mustang upper will fit under the hood I think. Want to say I read that when researching my 351W upgrade. But maybe not.....Someone running it will hopefully chime in.

I call BS on the "one of the first things that the mustang guys replace because the air flow is restrictive on a 5.0" until I hear it in context. I've had several Fox bodies and back in 1990, the GT-40 was really the only other option over stock. My 90 Fox ran like a scalded dog with just a few upgrades and the intake was not on of them. Heck, the air box on the Fox was a huge restriction no matter the intake you ran. The stock box had an "air silencer" attached to it. Removing it opened was about the same as putting on a cold air intake.

Tim

 

[lonesouth]

the truck lower, adapter etc route is a tall assembly. depending on body lift and hood configuration, you might be ok, but if not, you would run into hood interference. the lighting lower buys some clearance but are not so quick to find and spendy.

Hank

I'm not so sure on that. I'm running a truck lower, adapter, 1" spacer, t-bird upper. Now I'm not sure if it is the t-bird upper, but even with the 1" spacer, I'm barely clearing the driver side valve cover, not even enough room to run a PCV valve. Also, mine fits underhood with just a 1" body lift and standard engine mounts.

 

[hankjr]

I'm not so sure on that. I'm running a truck lower, adapter, 1" spacer, t-bird upper. Now I'm not sure if it is the t-bird upper, but even with the 1" spacer, I'm barely clearing the driver side valve cover, not even enough room to run a PCV valve. Also, mine fits underhood with just a 1" body lift and standard engine mounts.

maybe im getting confused with OEM truck sfi :-(

 

[hankjr]

I'm running the GT-40 lower and upper and even with a 1 BL, scoop was the only option and I had to modify the hood bracing. I would take a 3 ich or more BL to clear. The main issue the TPS sticks up high.

Tim

i was worrying about this. i have mine sort of mocked up and with 1"BL im like 1.5" to the bad clearance wise, and that is eyeballed and doesnt include the TPS yet.... I really wanted to avoid cutting the hood.

Hank

 

[lonesouth]

yup. stock truck lower/upper require a 3" body lift and hood scoop./bubble.

 

[RedLeg0811]

I have a 2" body lift for a ZF and a fiberglass hood, so I should be good with height.

I have an Explore 5.0 GT40 upper and Lower, and a 5.8 lower. I don't know what the cast iron/ marine GT40 intake cost, but the Lightening intake is going for around $600. With that cost might as well get the Eldelbrock upper lower as it will perform better than the GT40.

I will probably go the route of the truck lower, adapter, and 5.0HO upper. It is most likely not optimum, but I probably will not be able to touch anything on the used market better for under $200. Don't mind spending a bit more, but also want to have the money to finish the conversion to EFI. I can upgrade down the road.

I just wanted to see if anyone had any better ideas.

 

[mattt]

the truck lower, adapter etc route is a tall assembly. depending on body lift and hood configuration, you might be ok, but if not, you would run into hood interference. the lighting lower buys some clearance but are not so quick to find and spendy. I have no data on flow differences.

Hank

A few years ago, someone posted here the measurements between Lightning GT40 setup and truck lower/BC adapter/5.0 HO upper. From what I remember, I think the truck lower adapted version was actually shorter than the GT40 setup.

 

[Timmy390]

i was worrying about this. i have mine sort of mocked up and with 1"BL im like 1.5" to the bad clearance wise, and that is eyeballed and doesnt include the TPS yet.... I really wanted to avoid cutting the hood.

I didn't want to cut my hood but I didn't want to put a 3 inch BL on it either.

I just walked out and looked at my rig. With a 1 inch BL, the TPS stuck up a good inch higher than the stock hood. The front of the Explorer GT-40 upper where the mounting bold is hits the hood brace that runs down the center of the hood. I had to cut that brace loose from the front most cross brace and put in a 1 inch spacer and welded it back together. It all might fit with a 2 inch BL but it will be very close with little to spare. That's why I say 3 inch BL min when going 351W, GT-40 lower and GT-40 Explorer upper. The lightning upper might fit better but you're looking at $500 plus for the upper vs. $35 (what I paid) for the complete Explorer upper (upper, mass air sensor, T-body, hoses, pigtails, etc) at the local yard.

I don't know what the cast iron/ marine GT40 intake cost, but the Lightening intake is going for around $600. With that cost might as well get the Eldelbrock upper lower as it will perform better than the GT40.

Got my GT-40 lower cast iron version for $350 shipped. It was in perfect condition. I blasted off all the black powder coating and painted it cast aluminum. Looks great on my rig.

Tim

 

[00gyrhed]

truck upper lower big body lift and hood scoop

truck lower/adapter/mustang upper not so tall, it would have easily fit under my stock hood with 2" BL.

Hell I run a crappy Chinese aftermarket copy of the original Edlebrock RPM for the 351 and I run a phenolic spacer and to clear the extra tall finned valve covers needed to clear the roller rockers and still have room to my stock hood with 2"BL. I can even take the drivers side valve cover off without removing the upper.

The truck lower, adapter, mustang upper IS restrictive if you are building an engine to run 8000 RPM, doubt it would matter much on a 351 up to 5000 RPM, especially with E7 heads or worse, and most stock or RV cams.

I just didn't like the looks of it for my 393 even though it maxes out at 5000 RPM as well. Beside I fell into the whole need to rebuild heads, well for a few dollars more good flowing aluminum heads trap. Next need better intake don't want to limit the heads you know the whole early bronco hobby thing.

The Chinese aftermarket intake needed quite a bit of work port matching not only to the heads but also to itself and the throttle body. If you go that route they are pretty cheap.

 

[needabronco]

Keep in mind your speed shop buddy and all the guys saying you have to run an aftermarket manifold are talking apples to oranges! They want maximum performance and are running their engines at much higher RPM's than you ever will in your Bronco. They are loosing torque (what we need) at the lower RPM's (where we need it) in order to get those higher horsepower numbers. I rarely run my Bronco's engine over 3,000 RPM's, which is where most street/speed shop guys start making power...

A stock 5.8 lower mated to the mustang upper will do just fine for what 99% of Bronco owners do the their trucks. For torque you want longer runners, which is exactly what your getting with that combo.

 

[o2bnmud]

Hey Martin,

Come talk to me this weekend at the swapmeet, since I have a similar setup.

Tony

 

[Viperwolf1]

I didn't want to cut my hood but I didn't want to put a 3 inch BL on it either.

I just walked out and looked at my rig. With a 1 inch BL, the TPS stuck up a good inch higher than the stock hood. The front of the Explorer GT-40 upper where the mounting bold is hits the hood brace that runs down the center of the hood. I had to cut that brace loose from the front most cross brace and put in a 1 inch spacer and welded it back together. It all might fit with a 2 inch BL but it will be very close with little to spare. That's why I say 3 inch BL min when going 351W, GT-40 lower and GT-40 Explorer upper. The lightning upper might fit better but you're looking at $500 plus for the upper vs. $35 (what I paid) for the complete Explorer upper (upper, mass air sensor, T-body, hoses, pigtails, etc) at the local yard.



Got my GT-40 lower cast iron version for $350 shipped. It was in perfect condition. I blasted off all the black powder coating and painted it cast aluminum. Looks great on my rig.

Tim

The '96 explorer throttle body and TPS is shorter than the later years. I have fit those '96 parts with lightning/explorer intake, stock motor mounts, completely stock steel hood and 1 3/4" of body lift.

 

[RedLeg0811]

The GT40 upper I have is a 96 Explore.

Saw a cast iron GT40 for $350 shipped. Debating on getting it or not. I think I will probably go the cheap route for now since I also need an EFI wiring harness.

 

[RedLeg0811]

Hey Martin,

Come talk to me this weekend at the swapmeet, since I have a similar setup.

Tony

Tony, txted you about the 5.0 stuff you got from Larry.

 

[landshark99]

i picked up a 351 GT40 aluminum lower for $350 shipped off the classified section from a mustang Forum a month ago. If you watch the boards you will find a decent price if you want one however i was not in a hurry and was watching for some time

 

[Timmy390]

i picked up a 351 GT40 aluminum lower for $350 shipped off the classified section from a mustang Forum a month ago.

WOW....Nice score......

Tim