LD340 mod with TQ

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beepahh

Dart runner
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ok now has anyone modified an LD340 to have a thermoquad mounted on top??? looking for a template of machining cuts so I can put on my milling machine and cut out. I have heard of this done but never actually spoke to a driver that has one done......help out if you can .....there are a lot of people on this board with extensive racing knowledge I an lookig for your assistance...think about it one of the greates intakes made for a 340 with probably the best spread bore carb ever made

thanks - joe
 
Ive done it. I used a TQ carb gasket as a template and got out the die grinder.

IM000978.jpg


I also cut out the center divider but thats more of a race modification then a street thing.
 
Adam

wow it was that easy really.....ok let me ask you were you happy with the results and preformance updrade? also did you run a the thick gasket or the 1/16" thin one? let me know please

Joe
 
I had a thin gasket on it. I never got to drive the car but the guy who bought it says it run real strong. It had enough power to snap the snout off of the converter. The motor Dynod at 480hp with a Victor intake and 830cfm Holley. Not sure what it lost with the LD340 and Thermoquad but Im sure it was still good for 450.
 
Thanks Adam for the advice ....oh were you able to keep the 70 swinger you were selling???? I heard about you situation and can relate time are tough and people can be rough...... will need to pick your brain more often knowledge is king and you are great to share this with others cudos to you

do you have a 1970 dart ac/radio bezel for sale silver style...

Regards - Joe
 
Yes I was able to keep the Dart !

Im in need of the silver heater/radio piece also. Non A/C though.
 
Adam the moteo you had the LD340 on was it stoked o achievve that horsepower? what was the build up ?

oh there is a post on parts for a 1970 radio did you see it?
 
Adam

wow it was that easy really.....ok let me ask you were you happy with the results and preformance updrade? also did you run a the thick gasket or the 1/16" thin one? let me know please

Joe

I have also done the same thing to one of my LD340 intakes and the result was a positive one. I have used the intake with and without the plenum divider milled. Unless your going to use a cam similar to Adam's cam, do not mill the divider down.

NOTE; Becareful, someone before me wasn't and needed to weld alittle bit. Notice the outside peremiter of the carb base that needed some welding.

The milled divider trick was a trick used to help the intake get around the governing rules of the day. "No single plane intake of any kind, dual plane intakes only." Well, it is a dual plane intake. However once you mill the divider away you open up the plenum and shorten the runners into a large open plenum area. The intake starts to act like a single plane intake.

3rd picture down;
The addition of spacers add to the plenum as well. On a stock T-Q carb, this can be a problem with enuff pump shot and increase jetting, (An issue's with any carb.)

(Also pictured with the intake and spacers was an experiment on use of a electric choke on a T-Q. While I did get it to work, it was ugly.)

Overall, I did like the intake mod of just opening up the base for the T-Q. The advantage of a dual purpose carb that can breath very deep becomes apparent and works well with small to med. sized cams.

One of the first things I noticed over a square bore carb was the screaming top end of the T-Q. It earned me my first victory in a rematch over a Camaro that very night.

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Tkanks for the information did you cut down the center runner? the intake i have has a notch in the runner which looks stock to me for balance. What was the 340 build you used this on i want ot acheive 450 hp and was wondering if a 408 kit was reqiured. I have a stock 1971 340 with x heads never disasembled virgin motor. It was given to me by an old man that had it garaged for 25 years....would appreciate some advice would be nice to stay with standard rotating assembly
Joe

oh only 2 pics were sent
 
I did it afew years back, But for some reason mine didn't idle good with the carb bolted on the intake. Put a spacer on and it ran fine
 
The notch is actually to cleat the secondary throttle blade on Holley 3bbls.

450hp is possible from a 340, maybe not the most street friendly thing. It would be a lot easier with a 4" stroke.
 
sorry third pic is there you are very creative in trying to put choke on tq in lieu of the stock version.....real cool so over all the tq/LD340 combo is a winner right?
 
Adam what do you mean not street freindly....to radical because of all the cam required?
 
sorry third pic is there you are very creative in trying to put choke on tq in lieu of the stock version.....real cool so over all the tq/LD340 combo is a winner right?

Re read my post, I answered that question before you asked it.
 
thanks to all of you for advice and comments...will let you know outcome in about 2-3 months complete drive train upgrade will be done in my garage...
 
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