Replacement Carb for TQ

[hooD]

What would be a good replacement carb for the factory thermoquad 850 cfm?  My 340 is completely stock except for headers.  I'm looking for a carb that's equal to or better than the TQ without changing the intake manifold. 

On the other hand, would keeping what I have be wiser?  If its not broke don't fix it.

[Chryco Psycho]

IMO the TQ is the best spead bore carb , it works well
 Holley has some spread bore carbs that work well also & they can usually be found cheap at swaps etc , I would look for an 800 Holley spread bore just for ease of getting tuning parts if you decide to replace the TQ

[Bullitt-]

If your looking for more performance get a larger air-cleaner with a low restriction filter like K&N 

[farmertan]

  bullitt my kids are looking over my shoulder and laughing at your little monkey vid. Now back to the subject, Hood when i was trying to locate a date correct carb i found a guy in the detroit area that rebuilds them to like new cond. if you want i can give you his # . When they work good there a really good carb i would stick with what you have.

[femtnmax]

I agree totaly with all the other posts, especially the KN air cleaner.  IF your TQ is working ok, and you want more go go go, look at the rest of your package.  Depending on the year of your engine, there may be two jets screwed into the floor of the plenum under the carb.  These jets are to mix exhaust gas into the fuel/air mixture.  They are a smog deal, and act like pouring water on a camp fire.   You can remove the jets, weld the holes shut on the backside of the jet, then reinstall them.  May have to check fuel/air mixture afterwords.
Buy a good set of headers, good low restriction mufflers, and dual exhaust with crossover pipe.  My 340 really liked adding headers, if I remember right my car got better gas mileage even with my lead foot.

[71chally416]

  I agree too the air cleaner is inadequate. I myself would never replace a good Thermoquad with anything else. 

[hooD]

I agree totaly with all the other posts, especially the KN air cleaner.  IF your TQ is working ok, and you want more go go go, look at the rest of your package.  Depending on the year of your engine, there may be two jets screwed into the floor of the plenum under the carb.  These jets are to mix exhaust gas into the fuel/air mixture.  They are a smog deal, and act like pouring water on a camp fire.   You can remove the jets, weld the holes shut on the backside of the jet, then reinstall them.  May have to check fuel/air mixture afterwords.
Buy a good set of headers, good low restriction mufflers, and dual exhaust with crossover pipe.  My 340 really liked adding headers, if I remember right my car got better gas mileage even with my lead foot.

Back in 1974 I did remove the jets and I soldered them closed.  But when I was re-installing the last jet it dropped into the floor of the intake and I had to pull the manifold off to retrieve the jet.  What a pain in the rear.  I also have headers and a 3.91 sure grip rear end.

The TQ works flawlessly except for a slight fuel leak from the linkage rod.  It could use a good cleaning up on the exterior too.

[hooD]

bullitt my kids are looking over my shoulder and laughing at your little monkey vid. Now back to the subject, Hood when i was trying to locate a date correct carb i found a guy in the detroit area that rebuilds them to like new cond. if you want i can give you his # . When they work good there a really good carb i would stick with what you have.

That phone number could come in very handy....you can PM me anytime with it, thanks!

[hooD]

If your looking for more performance get a larger air-cleaner with a low restriction filter like K&N 

You know, I never thought that the smaller air filter was working against performance.  Where would I get the air cleaner housing from to use the K&N filter with?  I have my original air cleaner/filter set up from the factory. 

[hooD]

I agree too the air cleaner is inadequate. I myself would never replace a good Thermoquad with anything else. 

Well, I guess I will tidy up my TQ and increase its air breathing capacity with a larger filter setup.  I was only thinking that the TQ was lacking because of its age and that the newer carbs had an edge over it.  What do I know?

[71chally416]

A 14" x 4" with an Extreme llid would be a good setup. You'll probably need a drop base to clear the inner structure in the hood. You won't believe the howl the filter lid will make with a TQ. 

[femtnmax]

When you go to rebuild your TQ, if it has the black plastic floats replace them with brass ones.  The plastic ones will eventually absorb fuel and start sinking...gives the wrong fuel/air mix.
Also when rebuilding don't let some fool bead blast your TQ parts, doing so will remove the green "teflon" coating on the throttle shafts.  You want that coating.  Just use carb soak solution or gumout.  Gumout spray only on the black plastic float bowl carb center body.

[hooD]

A 14" x 4" with an Extreme llid would be a good setup. You'll probably need a drop base to clear the inner structure in the hood. You won't believe the howl the filter lid will make with a TQ.

If I use a K&N air filter, where do I get the base that fits onto the carb?  I wasn't going to use my factory housing.  I googled around, but they only come up with the round filter element. 

This place had these, but I'm not sure what size to look at.  http://www.streetsideauto.com/products.asp?PQCat1=1745&PQCat2=&PQCat3=&PQCount=3&ParentID=6&SubID=932&ptid=3397&brand=BBWQ&PQID=5664&series=X-Stream%3B+Air+Filter&lsbYear=1973&lsbMakes=PLYMOUTH&lsbModels=CUDA&lsbSubModels=None&lsbEngTypes=V8&lsbFuelDels=Carbureted&lsbASPs=Normal&lsbEngineSizes=5.6L+%2F+340+C.I.D.&lsbEngVins=H&VQString=None&APQString=None&LookupType=NON

[Chryco Psycho]

most places will have a 14" drop base filter , even K&N has them with a filter included

[Bullitt-]

I'd measure the OE boxes drop & maybe reinstall it & smash some playdough with the hood to be sure you have clearance, be sure to check their total height dimension.