Performer. Air Gap or LD340 Intake?
#69893
06/08/08 12:43 PM
06/08/08 12:43 PM
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Joined: Feb 2003
Posts: 607 NY
old340dog
OP
mopar
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OP
mopar
Joined: Feb 2003
Posts: 607
NY
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Which would be better for a stock 340 rebuild with 8:5 -9:5 compression and stock cam? A performer, airgap or LD340. I'd like to switch manifolds on my rebuild. Also which carb would work best. I've heard allot of good about the Barry Grant carbs.
old340dog
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Re: Performer. Air Gap or LD340 Intake?
[Re: old340dog]
#69894
06/08/08 01:21 PM
06/08/08 01:21 PM
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Joined: Jan 2004
Posts: 1,230 Pittsburgh, PA
wayfarer1
pro stock
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pro stock
Joined: Jan 2004
Posts: 1,230
Pittsburgh, PA
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What year 340 are you building? The LD 340 will not accept the later Thermoquad carbs. The Air-gap will perform and flow better and you can run any carb you want. I am using a Performer RPM on my stock 340 which is basically an Air-Gap without the flow thru design.
Joe
Current Project: 72 Roadrunner 340/727/Petty Blue/White Roof Strobe Stripe/Black Bucket Interior
71 Demon project
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Re: Performer. Air Gap or LD340 Intake?
[Re: wayfarer1]
#69896
06/08/08 01:27 PM
06/08/08 01:27 PM
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Joined: Jul 2003
Posts: 6,167 Maryland
GO_Fish
master
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master
Joined: Jul 2003
Posts: 6,167
Maryland
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* The LD 'in stock form' will not accept a spreadbore carb. It was however cast with intentionally thick bosses on the carb mounting surface, so it can be safely hogged out to accept a Thermoquad or other spreadbore carb.
Scott B.
"I'm a self-made man... I started with nothing, and I still have most of it!"
68 360 rusty B'cuda 'vert (GO Fish)13.59@ 98.72 mph
69 340 GTS stock 14.18@ 95.60 mph
01 5.9L Ram 1500 Quad Cab 4x4
01 3.5L 300M 16.23@ 86.97 mph
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Re: Performer. Air Gap or LD340 Intake?
[Re: ScottSmith_Harms]
#69897
06/08/08 01:43 PM
06/08/08 01:43 PM
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Joined: Feb 2003
Posts: 607 NY
old340dog
OP
mopar
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OP
mopar
Joined: Feb 2003
Posts: 607
NY
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Mine is a 73 340 motor. So it has the low compression 8:5. I though about seeing if I could boost the compression a little, but still keep it stock with a stock cam and use one of these intakes.
old340dog
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Re: Performer. Air Gap or LD340 Intake?
[Re: GO_Fish]
#69898
06/08/08 01:44 PM
06/08/08 01:44 PM
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Joined: Jan 2003
Posts: 25,200 Upper Midwest
MoparforLife
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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Quote:
* The LD 'in stock form' will not accept a spreadbore carb. It was however cast with intentionally thick bosses on the carb mounting surface, so it can be safely hogged out to accept a Thermoquad or other spreadbore carb.
And the difference in performance between the Airgap and the LD340 will so close as to say that if you already have an LD340 that the purchase of a new AIrgap would not be even close to a cost efficient move.
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Re: Performer. Air Gap or LD340 Intake?
[Re: old340dog]
#69899
06/08/08 01:46 PM
06/08/08 01:46 PM
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Joined: Jan 2003
Posts: 7,978 Bethel Ct
AdamR
master
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master
Joined: Jan 2003
Posts: 7,978
Bethel Ct
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If you have the LD340 I would use that. If you need a new intake I would go with a Performer RPM. The RPM and Air gap are the same runner and height only difference being the "airgap" under the runners. I doubt you will see any gain from that and I feel its not worth th extra $100 over the regular RPM
I ran a LD340 on a low compression 340 and it always ran hard. I also used on a 11:1 340 that was ported for a Thermoquad. Great intakes.
Dont under estimate the stock spreadbore 340 intake though. If you all ready have one they perform great as well.
Last edited by AdamR; 06/08/08 01:48 PM.
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Re: Performer. Air Gap or LD340 Intake?
[Re: ScottSmith_Harms]
#69900
06/08/08 01:58 PM
06/08/08 01:58 PM
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Joined: Jan 2003
Posts: 25,200 Upper Midwest
MoparforLife
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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Quote:
For a stock build I'd go with the LD340. If you plan on more upgrades (cam, headers, head porting, etc.) I'd go with the Air Gap, it has the most potential of all 3 in a performance build.
If going with a stock type rebuild and want a weight reduction go with the Performer littl eor very little gain there other wise. Performance build go with the LD340, RPM or Airgap. No comparison in any of these three to stock intakes and very close to each other.
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Re: Performer. Air Gap or LD340 Intake?
[Re: old340dog]
#69901
06/11/08 07:52 PM
06/11/08 07:52 PM
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Joined: Nov 2006
Posts: 511 Jasper, Indiana
fastnos
mopar
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mopar
Joined: Nov 2006
Posts: 511
Jasper, Indiana
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Gotta ask you a couple of questions first. Do you already have one or more of these intakes, or do you have to buy any one of them when you replace it? If building a 73 340, you might want to go with the earlier pistons and cam. 73's were lower compression and cam was a little different too. If your planning on going much over 5000rpm often, then you might look for a set of aftermarket heads. But just for a warmed over decent running 340, the factory ones will do fine. What do you plan on doing with it after the rebuild- daily driving with occasions of spirited driving, weekend warrior, or strictly a strip car with occasional street excursions? The cost of a rebuild for basically the same engine, earlier spec 340 vs. the 73 version should be close. The earlier parts should give you more bang for your buck tho. Just don't go too overboard. On a basic stock rebuild, I'd use the LD340 if you can buy it reasonable, and modify it to fit the Thermoquad. If you really want performance then go with an air gap and Holley of your choice, with larger cam. The LD340 was a great intake to begin with, and for street driving, it is a great piece. If you want to go a little faster, then you might want to get a junkyard 360 engine and go with a stroker version/kit for it. No need to go with a forged crank unless you want to go much over 450-500 HP. Cast cranks should last on a street car without too many problems. Just make sure your oiling system is up to par if you go that route. Let us know what you decide.
A True Hybrid: Burns Gas AND Rubber!
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Re: Performer. Air Gap or LD340 Intake?
[Re: MoparforLife]
#69903
06/11/08 08:52 PM
06/11/08 08:52 PM
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Joined: Apr 2007
Posts: 1,261 ILL
mark7171
pro stock
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pro stock
Joined: Apr 2007
Posts: 1,261
ILL
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Quote:
Quote:
For a stock build I'd go with the LD340. If you plan on more upgrades (cam, headers, head porting, etc.) I'd go with the Air Gap, it has the most potential of all 3 in a performance build.
If going with a stock type rebuild and want a weight reduction go with the Performer littl eor very little gain there other wise. Performance build go with the LD340, RPM or Airgap. No comparison in any of these three to stock intakes and very close to each other.
can going to a RPM from a perform manifold result in a loss of performance on a mild engine?
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Re: Performer. Air Gap or LD340 Intake?
[Re: mark7171]
#69904
06/11/08 08:58 PM
06/11/08 08:58 PM
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Joined: Jan 2003
Posts: 584 Los Angeles, CA
Freiburger
mopar
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mopar
Joined: Jan 2003
Posts: 584
Los Angeles, CA
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Not im my experience. The Air Gap will probably be better everywhere in the curve vs. a Performer.
Facebook.com/DavidFreiburger
70 Super Bee - 68 Charger - 68 Dart
75 Gremmie and 20-plus other junkers
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Re: Performer. Air Gap or LD340 Intake?
[Re: Freiburger]
#69905
06/11/08 09:12 PM
06/11/08 09:12 PM
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Joined: Jan 2003
Posts: 25,200 Upper Midwest
MoparforLife
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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Quote:
can going to a RPM from a perform manifold result in a loss of performance on a mild engine?
It would be a fluke if it happened. There is no comparison between the Performer and the Airgap.
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