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Discussion Starter #1
My son bought a 70SS 396 with a edelbrock high rise with 780 holley carb and non cowl induction hood. He change over to a cowl inducion hood and a stock CI air cleaner and the combination does not fit. The intake and carb sit about 3/4 of an inch too high to work. He knows where he can get a stock intake and quadrajet carb. Any thoughts out there on what he should do. Thanks Ted
 

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Depends on how original he wants it to look?I'd put on the CI hood and leave the rest the same.
I'm planning on doing a similar swap on my 72SS.
Is the other hood the dome hood? If so,do you want to sell? I'm interested.
Rick
 

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I was going to ask a question similar to Tom's ques. First, do you have the spacer between the carb and aircleaner? If so, will it fit if you just remove the spacer? If that won't work, will it work with the seal and flange removed? If that won't work, will it work with an open element air cleaner? If none of the above will work, then it is your call whether you want to hassle with changing manifolds. The factory setup is a lowrise intake, Q-jet, a 1 3/4in spacer and then the CI air cleaner with flange and seal. There is no question that the trick, best looking (as well as functional) setup is to have all the CI pieces installed so that a good seal with the hood is accomplished.

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Tom Parsons
 

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i want to go to a edelbrock performer rpm as well..but do not want to loose the cowl seal for appearance or performance in hot fla.....my current setup is a 287 low rise oval port stock manifold and holley 4011 carb...no spacers anywhere ..the cowl seal fits just fine but there is no way it would fit if i went to a high rise and kept everything else the same....

I did see a 70 CI car with a high rise and seal at the turkey rod run but the owner wasnt around so i couldnt ask him to show me how he pieced it together... i did line up the front and rear egde of the cowl seal visually and it coincided with the rubber cowl seal above the firewall...mine appears to be about 1" lower but i know the high rise is more than 1" taller than my stock 287 so i dont know what the difference is..either his cowl seal base is more lowered (did GM make more than one base for the airfilter/cowl seal??) than mine or the carb is simply shorter!

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Rich
Cocoa Beach, Fla
Team Chevelle #380
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www.chevelles.com/showroom/70_SS_454.jpg
 

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Discussion Starter #6
Thanks for your replies. I found out a little more info last night. My sons car has a Edelbrock performer 2.0 maniford with no spacer and just is to high. Unfortunately that leaves no option for a switch of spacers, and he wants the system to be functional so taking the flange ring and seal wouldn't work either. I did look at another 70 SS 396 car with a aftermarket edelbrock manifold that worked and was functional. It was a RPM manifold, with no spacer--worked fine. Rick sorry about the hood he sold it last summer to finance the CI hood. Thanks Ted.
 

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wait a minute ted...am i understanding that an RPM manifold will work but a performer wont??

what is the height difference...i thoought the rpm was HIGHER??

what carb is this with??

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Rich
Cocoa Beach, Fla
Team Chevelle #380
[email protected]
www.chevelles.com/showroom/70_SS_454.jpg




[This message has been edited by 70 SS 454 (edited 12-01-99).]
 

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Discussion Starter #9
Guys, thanks for the reply. I could go back and check but my son has the performer 2.0 with a 750 cfm holley carb, no spacer and the stock CI air cleaner. It is about 3/4 of and inch to high. The car I looked at had a edelbrock RPM manifold, no spacer and stock CI air cleaner. It just fit. Visually, the performer 2.0 is higher in comparison. The RPM manifold looks alot more like a stock cast iron intake to me. Anyway. his current set up runs nice and is on top of a 427 that been rebuilt by a previous owner, and I'm not real sure what it has for internals. My first inclination is to leave it alone but my son want the CI functional so we are trying to come up with a solution. Thanks, Ted
 

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I disagree with Ted that a Performer RPM will fit under a stock CI hood with the stock CI aircleaner and base. I have had two 70 SS cars with cowl-induction and I made the mistake of putting the Performer RPM on the first one - and it rubs the underneath side of the hood. My second car I used the Performer and it fit fine. One caveat - both cars had a Holley 3310 (with no spacer), not the stock Q-jet. I have heard of guys using a Corvette drop-down base to get the RPM to clear the CI hood ...

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Stan Hanek
'66 SS - 396 4 sp.
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the cowl induction base and seal etc IS a drop down base...

so whats the concensus here??? what fits with the stock base which supports the seal??..i dont want to loose the seal!!!

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Rich
Cocoa Beach, Fla
Team Chevelle #380
[email protected]
www.chevelles.com/showroom/70_SS_454.jpg
 

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On my 70 I have the factory cowl induction hood and the GM factory hi horse aluminum intake with a stock Holley carb.There is no spacer that sits on the carb and I have the stock cowl induction air cleaner with the seal and the whole thing fits like a glove.There was earlier discussion on this web site that some LS6 Chevelles came factory with this setup. Maybe mine is one of them.
 

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On my 70 I have the factory cowl induction hood and the GM factory hi horse aluminum intake with a stock Holley carb.There is no spacer that sits on the carb and I have the stock cowl induction air cleaner with the seal and the whole thing fits like a glove.There was earlier discussion on this web site that some LS6 Chevelles came factory with this setup. Maybe mine is one of them.
 

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rick..i beleive the "hi horse" gm aluminum manifold is not a HIGH rise...tho it must work just as well... would it be too much trouble for you to measue from the front edge of the manifold up to then base of the carb to get that vertical measuement... that will tell us if it is a high rise...
my reference says the 3977609 LS6 gm maifold is a low rise as is my 3955287 LS5 manifold and they both work just fine with the cowl hood/air seal...is that your casting numbeer by the way??

anyone have a 3977609 for sale????

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Rich
Cocoa Beach, Fla
Team Chevelle #380
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www.chevelles.com/showroom/70_SS_454.jpg
 

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Rich,
I went to the car took off the air cleaner and measured front edge of manifold to base of the carb which is 2 1/4 inch. The number on the intake behind carb is 3933198.
 

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This doesn't have much to do with topic but thought i would throw it in there. Whats the deal with these high rises? Do they work better then a non/low-rise instake or does the high rise act like a tunnel ram for just 1 carb? My understanding is that it was forcing the gas into the hole which gives more gas per detonation. Just wanted to make sure i was on the right track thankx.
 

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gumball...good question...my understanding is that a highrise offers a straighter shot for the air charge to enter the heads and cylinders making for more cylinder filling


therefore a tunnel ram should be better than a highrise which in turn should be better than a lowrise


rick..i dont have a reference that identifies that manifold...maybe someone else can help..

as best as i can measure, the carb mounting surface is about 2 3/4 inches above the front manifold/block interface on my 3955287 LS5 low rise manifold...mine is set up with a 3/8 heat insulator / gasket beneath the carb base and 3 gaskets at air horn...with a single gasket the bottm of the filter base binds against the carb...that exta 3/16 or so of the extra 2 gaskets provides adaquate clearance... no other spacer anywhere tho as i understand it , from the factory there was a spacer between the air horn and the filte base around 3/4 to 1 inch..on my set up that would really compress that air seal to the point of distortion i believe

anyone have a performer and performer RPM in the box that is easy to measure???


but then again, the general sure made a pretty ptotent engine (LS6) with a lowrise rect port manifold #3977609 so i sure dont know the answer... but that manifold sure would work with the CI hood/seal so maybe thats the answer...there was a previous thread that spoke of HP gains using rect port mainfolds with oval port heads so maybe this further supports the conclusion not to go to a performer rpm but rather the LS6 manifold

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Rich
Cocoa Beach, Fla
Team Chevelle #380
[email protected]
www.chevelles.com/showroom/70_SS_454.jpg


[This message has been edited by 70 SS 454 (edited 12-03-99).]

[This message has been edited by 70 SS 454 (edited 12-03-99).]
 
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