Need help choosing a carburetor
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Car: 1987 IROC
Engine: 350 Gm H.O
Transmission: 700r4 built
Axle/Gears: 3.42 Locker
Need help choosing a carburetor
I recently dropped in a 350 ho crate engine with my brother since the 305 decided to quit its life here. As of now I have my stock q jet on it with a cracked accelerator pump. But its still turning great thriottle response and 17 mpg. A mechanic told me that its really choking the motor and to go with a 700-770 cfm holley or demon. I am not sure on what to do.
Thanks for looking
Here is an article from car craft that used a 750 holley with good luck.
http://www.carcraft.com/projectbuild...all/index.html
Thanks for looking
Here is an article from car craft that used a 750 holley with good luck.
http://www.carcraft.com/projectbuild...all/index.html
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Re: Need help choosing a carburetor
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Very simple - fix the q-jet.
Here is an article from car craft that used a 750 holley with good luck.
http://www.carcraft.com/projectbuild...all/index.html
http://www.carcraft.com/projectbuild...all/index.html
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Car: 1987 IROC
Engine: 350 Gm H.O
Transmission: 700r4 built
Axle/Gears: 3.42 Locker
Re: Need help choosing a carburetor
What does that mean? I don't know, but I was told it when I had a mechanic adjust my kickdown cable and put a new choke on the q-jet. (I may be writing it wrong. I know very little about carbs and could be mixing it up with something else)
I noticed it was a double pumper, and read in my brothers holley double pumper manual that it will destroy a overdrive transmission. So that can't be good.
Thanks for the replies. I'm keeping my q jet and saving a lot of coin because of your help.
I noticed it was a double pumper, and read in my brothers holley double pumper manual that it will destroy a overdrive transmission. So that can't be good.
Thanks for the replies. I'm keeping my q jet and saving a lot of coin because of your help.
Last edited by IROCJoyce; 08-10-2009 at 08:28 PM.
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
It's not the "double pumper" part that destroys overdrive transmissions - it's the geometry of the throttle arm for the transmission throttle valve cable, which would also be the case with a vacuum secondary Holley or an Edelbrock Performer. The simple fix is to install a "geometry corrector" bracket.
But, keeping the q-jet is still the right answer.
What he might be trying to say is the accelerator pump is not working correctly because the pump plunger seal is cracked. If that was the case, it should be bogging or backfiring when you depress the accelerator pedal. But, you said it had great throttle response, so it isn't adding up.
But, keeping the q-jet is still the right answer.
What he might be trying to say is the accelerator pump is not working correctly because the pump plunger seal is cracked. If that was the case, it should be bogging or backfiring when you depress the accelerator pedal. But, you said it had great throttle response, so it isn't adding up.
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Car: 1987 IROC
Engine: 350 Gm H.O
Transmission: 700r4 built
Axle/Gears: 3.42 Locker
Re: Need help choosing a carburetor
Ahh okay, I understand it now. So its the geometry. Makes sense.
My brother has a 700 holley classic double pumper which I was going to use because its new. But I was afraid because of what the manual said. So a corrector bracket would allow me to put on a double pumper? Just wondering if his carb would have been okay on my motor if I did use it.
No backfiring, but there was a bad hesitation when I hit the gas once to aovid a person on their cell phone. Other than that I have been keeping my motor under 2500 rpm for break in.
Thanks for the info master moderator
My brother has a 700 holley classic double pumper which I was going to use because its new. But I was afraid because of what the manual said. So a corrector bracket would allow me to put on a double pumper? Just wondering if his carb would have been okay on my motor if I did use it.
No backfiring, but there was a bad hesitation when I hit the gas once to aovid a person on their cell phone. Other than that I have been keeping my motor under 2500 rpm for break in.
Thanks for the info master moderator
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