upgrade for performance
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Instructor
Joined: Sep 2006
Posts: 154
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From: Upper Darby PA
upgrade for performance
New guy here. have been monitoring the site for awhile and am impressed with the depth of Corvette knowledge. thanks for the education.
just purchased a California (originally from TN) 4 spd '81 with a ZZ4 engine and 3:07 rear. have applied for a PA classic tag, so there will be no emission test. want to remove the polution plumbing, install test pipe, change carb to a Holley 650 with a mech secondary, and an MSD system. in the spring, install headers and 2 1/5 inch exhaust. have noticed Demon is selling reman 650s for ZZ4s, so this is a consideration.
I know there are q-jet, Holley, and Demon devoutees out there, but am I on the right track for a Sunday street car with muscle ? maybe have some quarter mile fun once a week.
thanks, Rich N.
just purchased a California (originally from TN) 4 spd '81 with a ZZ4 engine and 3:07 rear. have applied for a PA classic tag, so there will be no emission test. want to remove the polution plumbing, install test pipe, change carb to a Holley 650 with a mech secondary, and an MSD system. in the spring, install headers and 2 1/5 inch exhaust. have noticed Demon is selling reman 650s for ZZ4s, so this is a consideration.
I know there are q-jet, Holley, and Demon devoutees out there, but am I on the right track for a Sunday street car with muscle ? maybe have some quarter mile fun once a week.
thanks, Rich N.
NCM Grand Opening Veteran
Joined: Sep 2005
Posts: 20,979
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From: South of giving a damn
St. Jude Donor '11, '17
Sounds like a nice ride. The ZZ4 pictures looks like it comes with a Qjet intake, is the intake also drilled for square bore carbs? If not, you'll need to chage the intake. I might suggest a vac secondary carb, although with a manual drivability won't be such an issue. The items you have planned to purchase should really wake this engine up.
Thread Starter
Instructor
Joined: Sep 2006
Posts: 154
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From: Upper Darby PA
thanks ratflinger, my guy at the local speed shop knows ZZ4s well, and he didn't mention changing the intake for the Holley. I know the Demon is OK. in trying to remember recent threads on carbs, it seemed the concensus was mech secondary on 4 spds and vac on autos. did I get it backwards ?
I'm buying the parts on Monday afternoon, unless I hear differently from the forum experts. also, I'll ask about the intake. Rich N.
I'm buying the parts on Monday afternoon, unless I hear differently from the forum experts. also, I'll ask about the intake. Rich N.
Melting Slicks
Joined: Dec 1999
Posts: 2,116
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From: Mid West
Cruise-In III Veteran
A Holley will work just fine on the manifold. If you go with a Demon, a 650 will work just fine, but you'll want to go with a 700 or 750 Holley. Demons are rated differently than Holley carbs and flow more air for a given size. They rate their carbs using an air & fuel mixture, and Holley has always rated theirs just by air cfm.
Also, if you can go with headers I recommend going with Dynomax's ceramic full length headers. Great looks, low cost, and great fit.
Also, if you can go with headers I recommend going with Dynomax's ceramic full length headers. Great looks, low cost, and great fit.
Thread Starter
Instructor
Joined: Sep 2006
Posts: 154
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From: Upper Darby PA
thanks Jason, didn't realize the difference between Demon and Holley in their rating methods. I have been rethinking the carb size after your comments, as the q-jet is a 750 used on the original 190 hp engine. the ZZ4 should be able to better use the capabilties of a 750 over the original. I am now leaning more to the 650 Demon or 750 Holley.
will either one or both be able to perform to their best efficiency after I install the headers and larger exhaust system ?
this was a lot easier 35 years ago when I sold my '68. Holley, Isky, Edelbrock, and Mallory were about it for selection of quality parts. no place else to go, but you got good performance for the day. lots of choices today. God bless America.
Rich N.
will either one or both be able to perform to their best efficiency after I install the headers and larger exhaust system ?
this was a lot easier 35 years ago when I sold my '68. Holley, Isky, Edelbrock, and Mallory were about it for selection of quality parts. no place else to go, but you got good performance for the day. lots of choices today. God bless America.
Rich N.
