Qjet for 2.29 axle? Why?

[malibu79]

I just get finally the right Qjet for my 79 Malibu 305 A/C TH200 2.29 axle : #17059222

I got the car with a #1705720 77 Chevelle/Vette 350 A/C auto trans

I never looked at the Carb# but a few weeks ago as i want to rebuild it and checked the numbers i was pretty surprised...Can anyone explain me why the carb is specially for a 2.29 axle? I‘ve found nothing but the jets/rods combo but thats related to the different displacement i guess
Any further info here? Thanks guys

 

[pontiacgp]

where did you find the carb was built for the rear gear ratio

 

[oldsmobile joe]

my guess is its set up for low rpm torque and fuel economy. national speed limit was 55mph back then.

 

[Bitterman]

I am interested in that sheet you are referencing. I believe I am also running a 2.29 axle. I'd like to check mine as well.

 

[Bonnewagon]

With a 2:29 I would have felt a Dual-jet was more appropriate.

 

[pagrunt]

With a 2:29 I would have felt a Dual-jet was more appropriate.

The parts car '86 had a 2.29 with 305 4bbl/TH200-4R. That's a out there combo but it was the '80's band-aid fix for better MPG's.

 

[Bonnewagon]

I fixed up a 1980 Firebird 4 barrel 301 2:41 gears for my Daughter in College. It sucked until I swapped out the 4 barrel and replaced with a Dual-jet and manifold. I knew this because my other Daughter drove a 1979 Formula 301 Dual-jet and 2:41 gears and it was peppy and thrifty. You gotta match the punishment to the crime.

 

[malibu79]

I am interested in that sheet you are referencing. I believe I am also running a 2.29 axle. I'd like to check mine as well.

It‘s the „Q-jet tuning paper“ by Lars Grimsrud

 

[malibu79]

where did you find the carb was built for the rear gear ratio
[/QUOTE

Attached above☝

 

[malibu79]

Adjustment and tuning specs , if needed..the complete sheet was too large🤷🏻‍♂️