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Discussion Starter · #1 ·
Figured I'd start a thread on this issue alone.
I have a 1980 El Camino that I'm building a 489 BBC for. Obviously hood clearance is at a premium in one of these A/G body vehicles. My car/truck is really nice so I don't want to hack up a perfectly good hood. The lowest aftermarket intake I've found is the Edelbrock Torker which is a full inch lower than most dual plane intakes. I'm used to dual plane intakes for street use but have never had an engine this big before. The cam I'm putting in is pretty mild even for a 454, (Howards hydraulic roller 229/235 duration @0.050") so one of my questions would be what kind of street manners would this engine have with a single plane intake? Has anyone successfully run a dual plane in a G-body and kept it under the hood?

The rear end as of this writing has 3.42 gears, and I'm running a turbo 400 trans. I'm actually leaning towards 3.08s for more street friendly highway use but don't know how a single plane would react to that. I have never run a single plane on anything so just have nothing to go on.

Can the people who have done this please tell me what worked for you? thanks in advance
 

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How attached are you to the factory engine crossmember?

Between a oil pan change, mount change to a front plate, and some crossmember trimming you can lower the engine several inches.
 

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Discussion Starter · #3 ·
I really thought I'd get more response on this. I've been looking through threads all day at gbodyforum and not one thread about what dual plane intake people have used that will fit under the hood. From all of the reading I have done today it appears that the torker 2 is a real piece of crap. The best I could come up with for a decent low rise dual plane is the Weiand street warrior which has just a slightly lower carb pad height than the performer from edelbrock and better intake runners. It's a nice piece. I guess that and experiment with drop base air cleaners?

It's been done a thousand times, and not just in g-bodies, I'm really surprised there hasn't been much of a response to this.
 

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This thread from Chevelles.com (Team Chevelle) will probably interest you, the original poster is looking for a low intake for his 489 BBC in a '79 Malibu.....which is the same chassis and front sheetmetal as your '80 Elky.

(9) lowrise vs air gap power | Team Chevelle (chevelles.com)

Brodix has a dual plane that is supposably? no taller than a stock intake, but gives up nothing power-wise on the 720 HP 540" BBC Scott Shafiroff Racing build.

 

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I wanted a flat hood on my 81 Trans Am with a BBC. Used a stock cast iron intake as it's lower than anything else, except the BBC Corvette one which is just ugly.
I mocked up the block with the mounts and ended up cutting about 1" out of the clamshell that bolts to the block and welding the frame mount to the crossmember so that I had about 1/4" between the crossmember and the oil pan. Steering hit the pan sometimes, rubbed the paint off.
With a Corvette air cleaner it just barely worked.
 

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ZZ572 im my old 67 Elky, although I had a cowl hood it was steel and prob gave less room that the flat hood. As suggested you may want to drop the motor AND you can save many inches if you choose the proper air cleaner (and get more airflow)

617340
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I know that GM started using aluminum intakes in the 80’s and that they used bbc into about the mid 90’s in trucks. I wonder if you can find an 87 or so, stock bbc intake and if it would be aluminum, and will it work with your heads.

Bad part is, it might be spread bore only, just means you need to get a qjet
 

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I guess we take "I thought I'd get more response" as a challenge sometimes, huh...

Re: front crossmember, let me tell a story. My second El Camino was a '70 SS396cum427, cum 350, a rare bucket-seat/4 speed car which was why I wanted it. It turned out to not be a good driving car by any means, partly because it had shakes and shudders all over. I went so far as pulling the body and fabricating a rear crossmember to crutch-up the torn original, and replacing the right front frame rail which had prior weld repairs, without removing the engine. Car still jiggled like Charlie's Angels any time you did something like cross railroad tracks, there was one particular spot on the freeway I passed daily during my work week which made it do that and I grew to absolutely hate it. Eventually I wanted to do a resto, return a BB, etc. and pulled the body off again and this time the motor also. I just figured I'd probably try to do a bunch of bracing to cure the shudders, although my buddy had a BB Chevelle same year which had none of that problem.

Besides having the previously addressed type cracking all over the frame from it's one-time street-racer use plus over-dependence on air shocks, there was one more problem area, the front crossmember. Someone had cut it out for a big oil pan and reduced it from a box into a mere channel, and then welded in a bit of plate to box it again only in a reduced cross section area. I had never seen that with the motor in the way. That is all it took to turn a normal a-body into a limp spaghetti. Turns out, the front crossmember is really in the middle of the only torsional stiffness such a frame has, there are no other points to provide it, the trans crossmember is too small and the rear crossmember is open-channel which is easily twisted. That perimeter frame --needs-- some torsional stiffness.

So I went to the Pick-Your-Part and got another frame, with that damage being the final straw. Torched and scrapped the original. Good move, worked perfect when it was all done, no problems. I occasionally mention here I still have the car, 35 or so years later only now in a barn after a hundred-thou-plus I put on it.

So be careful what you do to that front crossmember. Lowering the engine within it would also get your oil sump down where it's going to get hit by something also...there is just no room there. If you really wanna keep the top of your motor under a flat hood you'll have to do it with crappy intake manifolds, Corvette-style. I do have a stock '72 BB 'Vette (project) and yeah, unless you want to add clearance the intake situation sucks.
 

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BTW, looking around a bit gets me the Brodix intake mentioned by Ericnova above, HV 2017 for oval-port and 2016 for rect, 5.175" tall which if they mean measured from the sealing surfaces at the ends is still much taller then the crazy-low 'Vette 3 1/2" but might work elsewhere such as on the G-body? You'd have to measure, I'd guess it's similar to the late-'60s passenger-car Q-Jet and Holley cast-iron oval port intakes. hv2017 | JEGS
 

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Read post #16.
Thats the route I recommend if you want to trim the crossmember.

 

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In reference to the Brodix #2017/2018, the stock manifold they are comparing to is not the common stock iron passenger car/light truck oval port manifold....they are comparable to the factory performance aluminum "high rise" from the 396/375 HP, 427/425 HP, and 454/450 HP engines.
Also very similar is the modern GM Perf verion used on current 454 HO and 502 HO crate motors. #19131359 Rectangle port, 12363420 Oval Port.
The Oval port version is 5.25" tall at middle of carb pad.

It is like a BBC version of the Z-28/LT-1 factory aluminum "high-rise" dual plane, from those two solid lifter hi-perf engines.

Jjjaffo, what intake did you use to put the 408 in the G-body Cutlass, your previous build?
Did the carb hit the stock hood, even with no air cleaner? Or did it fit but absolutely too tight, no room for air filter?
 

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Discussion Starter · #13 ·
In reference to the Brodix #2017/2018, the stock manifold they are comparing to is not the common stock iron passenger car/light truck oval port manifold....they are comparable to the factory performance aluminum "high rise" from the 396/375 HP, 427/425 HP, and 454/450 HP engines.
Also very similar is the modern GM Perf verion used on current 454 HO and 502 HO crate motors. #19131359 Rectangle port, 12363420 Oval Port.
The Oval port version is 5.25" tall at middle of carb pad.

It is like a BBC version of the Z-28/LT-1 factory aluminum "high-rise" dual plane, from those two solid lifter hi-perf engines.

Jjjaffo, what intake did you use to put the 408 in the G-body Cutlass, your previous build?
Did the carb hit the stock hood, even with no air cleaner? Or did it fit but absolutely too tight, no room for air filter?
When I originally put the car together I used an rpm air gap and cut a hole in the hood. When I redid the engine a few years ago I took out the 280 magnum cam and put in a 270 magnum along with a Weiand street warrior intake which is shorter than even a performer intake. Torque down stairs went up substantially!
Anyway, because of the hole in the hood I never measured to see if it would fit under the hood with a drop base. I know the torker 2 is the lowest but I hear it's a real piece of crap and the outer ports are smaller than the inner ones. WTF?
The weiand street warrior also has bigger runners than the edelbrock rpm I believe. If my Cutlass wasn't so far away I'd try to measure things for myself. As of now all I can do is ask people online their experiences.
 

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Discussion Starter · #14 ·
Read post #16.
Thats the route I recommend if you want to trim the crossmember.

I appreciate the suggestions, cerial, but I want to keep the original cross member.
 

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Discussion Starter · #15 ·
BTW, looking around a bit gets me the Brodix intake mentioned by Ericnova above, HV 2017 for oval-port and 2016 for rect, 5.175" tall which if they mean measured from the sealing surfaces at the ends is still much taller then the crazy-low 'Vette 3 1/2" but might work elsewhere such as on the G-body? You'd have to measure, I'd guess it's similar to the late-'60s passenger-car Q-Jet and Holley cast-iron oval port intakes. hv2017 | JEGS
A weiand street warrior intake has a pad height of about 4.80". It's just a fuzz lower than a performer. I think the Brodix will be too tall to work with.
 

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Discussion Starter · #16 ·
I wanted a flat hood on my 81 Trans Am with a BBC. Used a stock cast iron intake as it's lower than anything else, except the BBC Corvette one which is just ugly.
I mocked up the block with the mounts and ended up cutting about 1" out of the clamshell that bolts to the block and welding the frame mount to the crossmember so that I had about 1/4" between the crossmember and the oil pan. Steering hit the pan sometimes, rubbed the paint off.
With a Corvette air cleaner it just barely worked.
Hmmm, this is something worth chewing on as a last resort. I don't know what my crossmember/oilpan clearance will be yet.
 
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