Stock Intake or LD340?

-
SB69GTS

SB69GTS

Well-Known Member
Joined
Oct 21, 2009
Messages
421
Reaction score
17
Location
Ontario
Running a 69 340 Dart GTS, Have a original 1969 stock intake for it and know a guy who is selling a LD340 pretty cheap, what would you guys run, was trying to keep it pretty stock and original, but the price is leaning me to the dual plane .... also does anyone know what stock carb came on a 69 340 and if I go with a LD340, what would you guys match it up with. Let's see if we all kinda agree on this topic ....later
 
...............The LD340 is a great intake, even by 2days standards.......Id put it on........stock carb is an AVS Carter.........I have 1 if u need it......thats what id use........there a great carb.............kim..........
 
Depends what you're going for, resto look or performance cause like everyone else said..the ld340 is a great intake and pretty much equal to an rpm.
 
oldkimmer said:
...............The LD340 is a great intake, even by 2days standards.......Id put it on........stock carb is an AVS Carter.........I have 1 if u need it......thats what id use........there a great carb.............kim..........
Click to expand...
Can u pm me with a price and size that these were running in 69

Thanks
 
Stock intake with a 1" 4 hole spacer is a darn good option.

I like the LD340 because it works great. No spacer needed except if linkages hit the manifold
 
if your wanting to get every last bit of power go with the LD and a holley 700 or 750, if your wanting to keep it stock looking keep the iron intake add a 4-hole like stated above, block the heat crossover and use a avs off a 440 they flow about 100 cfm's more about 700 to 725cfm
 
When I had the stock 340 in my car I ran the LD340 intake and just painted it engine color. No one knew it was there. I now run the same LD340 on my stroker small block and love it. The stock intake is a very nice piece but way too heavy. Get rid of some weight up there, put that LD340 on. And the Carter AVS will bolt right up to an LD340.
 
Lionheart
Since I care about stock, and numbers matching SOOOO much...LMOA
Definitely go with the LD340, I took the, milling the center divider down to 1/2" off the top landing, route. An old hot rodders trick back in the 70s. Thats what ill be running on the stroker.
Also do the simple chore of gasket matching the heads and the intake.

Andrew
 
I have yet to compare the milled divider vs a non milled divider. I have 2 LD340's just to try this. The MP book says go to 3/8th I think it was.

Port matching the intake should be easy because not only is aluminum easy to grind away, but Edelbrock casted the ports large...very large. The ports are bigger then the RPM's ports.
 
OK .... Bought the LD340, now just have to line up a good carb for it ..... is the holley 750 not to big for a 340, was reading around to try and stay around the 650cfm ... lots of guys are staying with the carter ...but I guess this can open up a can of worms on which would perform better with a LD340 intake on a 69 340.....anyone one to try... love to hear your pros and cons on a 750 holley.
 
This is clearly a "Choose your poison" issue.

The Factory used the smaller carb for increased throttle response and overall all around driveabilty. Also, considering that for the most part, the cars came off the line with a 3.23 or 3.55 gear ratio. This smaller carb works very very well with that ratio and OE tire size.
 
I have run 750 vacuum carbs on both auto and 4 speed cars with basically stockish cammed engines with really good success.

Last one ran 13.30's at 102-103.

If you have gears and a converter or a 4 speed, a 750 DP could work when tuned properly.
 
For you're average performance motor- cid x 2 usually works good as a base line or within the realm cfm wise.
cfm
225=450/500
340=680/670-700
360=720/750
383=766/750/800
400=800/800-830
440=880/850-870-900
 
I usually go a little bit bigger on the carb size and then rejet it down. Most of my cars liked the increased airflow of the bigger carb and the smaller jets of the recommended carb size. I ran an 800 dp on a 340 with a 284/484 purpleshaft and a torquer 340 intake and 273 adjustable rockers with 1 5/8 headers. This setup was pretty mean in a street car with a 3k stall and 391's.
 
Sounds like a fun car!
I like the easy CID X 2 method as a base for performance, all around in general, it works well.

That calc is garbage IMO.
 
My 273 REALLY, REALLY liked the 71 340 TQ @ 750cfm. That's the beauty of having infinately adjustable doors on the secondaries, like a TQ, AVS, and even the lowly Q-Jet. I don't believe any of the formulas. If you want to go fast you have to have the flow.
 
1bad340Demon said:
I usually go a little bit bigger on the carb size and then rejet it down. Most of my cars liked the increased airflow of the bigger carb and the smaller jets of the recommended carb size. I ran an 800 dp on a 340 with a 284/484 purpleshaft and a torquer 340 intake and 273 adjustable rockers with 1 5/8 headers. This setup was pretty mean in a street car with a 3k stall and 391's.
Click to expand...

Oh yeah you can stick the biggy on there and make more power, just requires the stall/gears like you did or it'll suck response wise till 4000rpm even with timing fiddled.

At a certain point other things come into factor, like the cid thats under the port volume of the heads, once the the rpm exceeds the ideal PV the air speed is so great that it will activate/signal the bigger carb just fine and make use of the extra air flow=hp
In other words stockish heads on a 340 that spins 7500 rpm with 'gears'/comp, will eat up 800 or more cfm, on the street though.. at a certain point some carb fiddling needs to be done in order to have a decent working transfer circuit.
 
yeah if I followed that 4 sec calc my 340 that made crud with a 650 and then hauled azz with a 750, must have 110% volumetric efficiency.lol

It says I need a 729cfm for my 410. ha ha ha
 
You must log in or register to reply here.
-

Back
Top