upper intake for 351 efi

[777mechanic]

starting to gather parts such as mass flow , sensor , throttle , . question what size mass flow and injector do i need , next question what size, year , upper intake will fit my 91 5.8l speed density motor

 

[needabronco]

You'll either need to pony up for a lightning 5.8 GT40 lower and get a matching upper, or go with the BCB adapter plate and use a mustang style upper.

 

[70EB]

You have four choices:

1. 351W GT-40 lower with either a GT-40/Cobra/Explorer upper intake (good place to look for the lower is www.corral.net)

2. Edelbrock 351W EFI lower and Edelbrock 5.0 upper.

3. 351W truck lower, BCB adapter and then Mustang upper

4. 351W truck lower and upper (will have trouble fitting under stock hood even with 3" body lift)

I run a 351W GT-40 lower, Cobra upper, 65mm throttle body and 75mm MAF, with 24lb injectors.

 

[777mechanic]

going with the 5.0 upper will that cause a restriction of air , the motor will be pretty much stock other than cam and headers. has anyone tried porting the 5.0 upper or is it to thin to do that .

 

[flousberg]

Buy this and be done.
http://store.summitracing.com/partd...840125+4294822100+4294757145+115&autoview=sku

 

[carter2772]

Buy this and be done.
http://store.summitracing.com/partd...840125+4294822100+4294757145+115&autoview=sku

Do you know what kind of efi wiring you need to make that work? Just a mustang harness and computer???

 

[777mechanic]

Buy this and be done.
http://store.summitracing.com/partd...840125+4294822100+4294757145+115&autoview=sku

i've looked at that before , but it says it comes in around 1500rpm so do i need to worry about that or is it ok for the set in described, also what size in mm mass flow do i need

 

[Broncobowsher]

You have four choices:

1. 351W GT-40 lower with either a GT-40/Cobra/Explorer upper intake (good place to look for the lower is www.corral.net)

2. Edelbrock 351W EFI lower and Edelbrock 5.0 upper.

3. 351W truck lower, BCB adapter and then Mustang upper

4. 351W truck lower and upper (will have trouble fitting under stock hood even with 3" body lift)

I run a 351W GT-40 lower, Cobra upper, 65mm throttle body and 75mm MAF, with 24lb injectors.

I can think of 3 more options not listed
The Trick flow as mentioned between these posts
Price motorsports 302 to 351 intake adaptor
Custom sheetmetal low profile upper intake

The BC adaptor should work fine for low RPM applications. If you are building it to have strong power over 4500 RPM then I would consider the GT40 or aftermarket intake systems
As for porting the upper there is a big problem about getting all the debris out of the plenum. I bought an upper intake that had been blasted. The carbon deposits stick the the debris. The only way to really clean it is to cut the side off the upper intake, clean (and port) and weld the casting back together. If you really have a lot of time and can get aluminum welded back together it may be an option. But it isn't really the best of the options. The main intake runner off the throttle body is still a choke point that isn't easily fixed on the inline runner intakes. The staggered port (GT40 style) give more room for the throttle body feed.

 

[777mechanic]

hey this guy just called and has a upper and lower gt40 for 150. also has throttle body and maf . how much should i pay for those 2 items. there off a 96 explorer

 

[flousberg]

Those are for a 5.0. You can sell the lower because it won't work on you 5.8. The upper will work with a GT40 lower. I don't know what they run these days, I paid $280 about 4 years ago. The throttle body will work. You don't need the maf, you will have to reprogram your computer for it to work correctly. I don't know what part of the country you are in, but here in Denver there are a ton of 5.0 explorers in the junkyard and you could get those parts for $25 bucks each, so $50 bucks for the parts you need. That is at U pay and pull. I don't know what you budget is, but I still think the trick flow is the way to go for the 5.8 and I think that is the way I would go if I did it again. I believe it is about 1/2" lower than the GT40 also.

 

[805tony]

Buy this and be done.
http://store.summitracing.com/partd...840125+4294822100+4294757145+115&autoview=sku

Go with the Trick Flow!!!!!!!!!

 

[mr.n]

Go with the Trick Flow!!!!!!!!!

Wish I had your budget...


I'd keep the stock lower, and port it. Then get a knock off upper.
The restriction to flow are the heads, then the lower intake and manifold.