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Need help for edelbrock head

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Old Jun 1, 2008 | 07:27 PM
  #1  
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Default Need help for edelbrock head

I want to put some edelbrock RPM heads on my 1981 Corvette. I already have the edelbrock RPM intake, stock cam, stock Qjet, headers without cat.

First I want to know which one to choose for the best fit :

PERFORMER RPM WITH ANGLED PLUGS
Chamber Intake Port Valve(in/ex) Bare(single) Complete(single)
70cc 170cc 2.02"/1.60" #60619* #60719*
64cc 170cc 2.02"/1.60" #60949* #60999*
PERFORMER RPM WITH STRAIGHT PLUGS
70cc 170cc 2.02"/1.60" #60639* #60739*
64cc 170cc 2.02"/1.60 " #60889* #60899*

Second, can I bolt on directly or I need to modify roller rockers, or something like that.

Thanks
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Old Jun 1, 2008 | 07:58 PM
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Default

Originally Posted by pat80
I want to put some edelbrock RPM heads on my 1981 Corvette. I already have the edelbrock RPM intake, stock cam, stock Qjet, headers without cat.

First I want to know which one to choose for the best fit :

PERFORMER RPM WITH ANGLED PLUGS
Chamber Intake Port Valve(in/ex) Bare(single) Complete(single)
70cc 170cc 2.02"/1.60" #60619* #60719*
64cc 170cc 2.02"/1.60" #60949* #60999*
PERFORMER RPM WITH STRAIGHT PLUGS
70cc 170cc 2.02"/1.60" #60639* #60739*
64cc 170cc 2.02"/1.60 " #60889* #60899*

Second, can I bolt on directly or I need to modify roller rockers, or something like that.

Thanks
Both straight or angled will be fine,i just bought victor jr angle heads and the angle will be tight getting to your plugs,but they make short plugs so no problem with angle plugs heads either.The cc depends on how much compression you want,64 will give you more compression and the 70cc will give a little less.
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Old Jun 1, 2008 | 09:25 PM
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Originally Posted by Billysvette
Both straight or angled will be fine,i just bought victor jr angle heads and the angle will be tight getting to your plugs,but they make short plugs so no problem with angle plugs heads either.The cc depends on how much compression you want,64 will give you more compression and the 70cc will give a little less.
straight or angled : Whats the difference ?

64 or 70cc : Whats the difference ?
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Old Jun 1, 2008 | 10:29 PM
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I'm not sure about straight as apposed to angled but I do believe the smaller the CC the higher the CR n the bigger the CC the lower the CC....I'm sure some of more knowledgable will chime in with more info....Jerrylee///
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Old Jun 1, 2008 | 11:26 PM
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From: State of Confusion
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Originally Posted by pat80
64 or 70cc : Whats the difference ?
I 'assume' your '81 Corvette came with heads having 76 cc (cubic-centimeter) volume combustion chambers, resulting in a compression-ratio of about 8.2:1 ~

using heads with smaller chambers will raise the compression, giving you more HP/TQ:
70cc heads will yield about 8.7:1, while the 64cc heads may provide squeeze as-high-as 9.3:1
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Old Jun 2, 2008 | 06:34 AM
  #6  
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pat80
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And this :
Bare(single) Complete(single) ?
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Old Jun 2, 2008 | 06:40 AM
  #7  
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Originally Posted by pat80
And this :
Bare(single) Complete(single) ?
without looking at the link, 'bare' would refer to the 'bare' castings themselves, with no related pieces, like valves, valve-springs, or possibly even rocker-studs:
'complete' would probably mean just add head-gaskets, head-bolts & rocker-arms
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