Any reason why I shouldn't run a carb hat on EFI?

[Scorpion]

I've got a 74 LWB I've been working on for a hand full of years. Amongst the upgrades is a 9:1 454 with an RV cam. I'm mid swap on the next round of upgrades (saddle tanks to rear tank conversion, FAST EFI, new fuel lines, 4L80E, NP241 with SYE, bla, bla). Anyway, on one of my parts gathering trips I found a new looking air box out of a late model GM (similarly motivated). I was thinking of running the late model air box instead of the traditional air cleaner. I can't for the life of me remember why it seemed like such a good idea but it had something to do with less under hood noise than an intake kit and, when installed correctly, fresh air as the source. So to the question: The air box has a 4-inch inlet (round). Some mandrel bent tubing and silicone couplers connected to a carb hat like devise will get the carb to the box but is there a reason why a carb hat shouldn't be used in standard carb/efi applications? I can't think of any reasons but also don't see them very often so the thought crossed my mind. Even if I don't end up using the factory box and go to a cone style filter I still need some form of adapter to the carb and a carb hat or one of those modified air cleaners (for ram air setups) would be needed regardless. I had a K&N style intake on another project years ago but can't find it anymore. Will it work or be restrictive? Thanks.

 

[HotRodPC]

Welcome to GMSB Matt.

So I assume by Carb Hat... Do you mean the standard air cleaner on the intake plenum???

If it were me, I think I'd go with retrofitting the OEM Air Box that you said you found. Being a 4x4 I guess you might be concerned of having your air intake to low and sucking water or mud into it. If that wasn't the case I'd say you can also put holes in the bottom of the air box (pre filter) to get more air in, and could even run 2 with air ducts in the bumper. That works good for on road trucks but as said, we're working with a 4x4. I've also seen guys, and probably what I'll do on my 4x4, is use the cowel for an intake source with a duct tube to the side of your air box, along with the OEM design so you've essentially increased your air intake capability if needed.

This does sound like a nice build project. Got any pics of it? We're Pic ****** here and like lots of pics. We even have the space to host the pics for you unlike many forums who have a tiny ass limit for pics.

 

[MrMarty51]

I wonder, does the 74 have the round knockouts like the 79 ???
If so, could`nt an air cleaner assembly from, about an 89-90 Suburban/pickup fit, or, be made to fit ??? it ducts into fresh/cool air from the right side of the radiator/radiator support.
Yeah, welcome to the forum Matt, good to see new people coming in.
Also, I would think it to be nice to see one of those smilie, icon things that would be like this, :thisthreadisworthlesswithoutpics: or something of the sort.

 

[Scorpion]

QUOTE=HotRodPC;176614]Welcome to GMSB Matt.

So I assume by Carb Hat... Do you mean the standard air cleaner on the intake plenum???

If it were me, I think I'd go with retrofitting the OEM Air Box that you said you found. Being a 4x4 I guess you might be concerned of having your air intake to low and sucking water or mud into it. If that wasn't the case I'd say you can also put holes in the bottom of the air box (pre filter) to get more air in, and could even run 2 with air ducts in the bumper. That works good for on road trucks but as said, we're working with a 4x4. I've also seen guys, and probably what I'll do on my 4x4, is use the cowel for an intake source with a duct tube to the side of your air box, along with the OEM design so you've essentially increased your air intake capability if needed.

This does sound like a nice build project. Got any pics of it? We're Pic ****** here and like lots of pics. We even have the space to host the pics for you unlike many forums who have a tiny ass limit for pics.[/QUOTE]

I've seen them called carb hats or bonnets? Not sure what they're really called. Here's what I've been looking at.

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My goal is to adapt the 4" air box to the Fast EFI throttle body

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I don't want to cut holes into the bottom of the factory air box because that can let additional crud in the box during winter or wet months (I live in Colorado).

 

[Scorpion]

Is there any performance reason why any of the above setups would prevent airflow? Maybe that's the question...

 

[Jims86]

Is there any performance reason why any of the above setups would prevent airflow? Maybe that's the question...

You would be fine with a standard air cleaner, plumbed into the radiator support, otherwise, option 2 in your pics is the one I would go with.

 

[Scorpion]

You would be fine with a standard air cleaner, plumbed into the radiator support, otherwise, option 2 in your pics is the one I would go with.

I think that's the cheapest one and will look the cleanest under the hood. Think I agree.

 

[HotRodPC]

I'd like the dual one with duct work to both sides of the radiator, or down low into the bumper, or even into real fender vents like the Z28 Camaro's had. I normally don't like that fender crap, but when it's real and functional, then I think it's bad ass. The dual IMO will give the Muscle Car appearance and if it's real and functional, then hell yeah. Go for it.

 

[Driver4r]

Since your gonna be on the top of your engine, i would recamend either a single, or duel air horn.
Heres what i would recamend:
http://www.spectreperformance.com/i...r-dominator-dual-inlet-polished-aluminum.html

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Heres what im planning on running:
http://www.spectreperformance.com/i...-y-pipe-130-degree-with-6-90-degree-legs.html

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(im gonna be running a ls TB setup.)