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fastguy1958

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Reply with quote  #1 
Will this carb work okay on a SBC 434 with 230 dart pro 1 heads and 675 lift roller cam approximately 650hp 14.1 ..dart intake..5000 stall power-glide in a 2000 lb roadster shifting at 7000 rpms on 112 race fuel. or is it too big for that combo
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Reply with quote  #2 
Your converter is high enough and the vehicle is light enough that I would certainly put it on there.  An annular booster design MAY be a little faster, but if that leaves the line hard, it'll go the rest of the way hard.  If its lazy on the leave and its jetted for best mph, then its too big.  
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fastguy1958

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Reply with quote  #3 
what cfm is that carb
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Reply with quote  #4 
986 wet cfm.
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fastguy1958

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Reply with quote  #5 
can you tell me what jets this carb was built with. It had 78 in front with power valve and 86 in back when i got it used, I changed to 90 square with no power valve and picked up 5 mph and .08 in 1/8 mile. would bigger jets yet me advised. Plugs have no color after 5 or 6 passes
fastguy1958

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Reply with quote  #6 
ps I ran 9.06 at 140 mph in quarter shouldnt it be more like 150
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Reply with quote  #7 
Yea wow, someone had that jetted WAY down from proper and from how we shipped it.  Put it back as fast as you can!!  It was set 84 in front and 92 in the rear for HOT weather where they lived in Springfield MO altitude.  SO if you have it on the same or similar combination and area I would go up 2 main jets from there as a baseline.  86 front and 94 rear.   So you still may be 4 main jets too lean if the prior data and combinations are similar.  Or 94 square if you dont run a power valve.
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fastguy1958

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Reply with quote  #8 
the throttle blades on the carb have been drilled with small holes. is this something that you do or did someone do that after it left. I having a problem with consistent idle, it will idle perfect sometimes then become very erratic and even shut off when driving up to the staging lanes  I just now blew out all the holes but haven't reinstalled it. discovered that one mixture screw was missing the O ring. could that cause the problem. Also the idle jet hole  in the top of the carb is very tiny almost looks like a blank.
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Reply with quote  #9 
All of those things are correct, BUT your idle mixture screw definitely needs to be sealed up as that can cause the issue.

The idle air bleeds were originally .076 so they are quite large.  

See photo. airbleeds4150.png 



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