85cutlass6.6

What should i get for a carb for my .040 over 403 olds? I want man. Choke double pumper

J-(Chicago)

Double pumpers are for drag racing. I wouldn't bother with one on a street car.
Qjet, edelbrock, carter, thermoquad for a street car.
If it is going to race some, you could use a vacuum secondary holley

jag1886

I agree I love Holleys they are very easy to work on. I have always had way better results using a vacuum secondary carb unless you have a pretty hairy rebuild and a stick. Carb size depends a lot on your build and gearing. I used to have an old Impala with a built 427 (11-1 compression 2.19 Alumi heads big cam) 4 speed and a 4:56 gear, it loved a DP carb.

SBORule

I run a Barry Grant Mighty Demon 750 double pumper on my little 350 that only has a 9.3 to 1 static compression ratio with ported iron heads an 3.73 gears with 275/60/15's tires on the rear and it runs excellent on the street.

Now if you want to get decent gas mileage with such a carb, you got to learn to feather the gas when taking off in street traffic so you do not pump and dump alot of raw fuel by over working the accelerator pump/pumps.

You won't even activate the secondary accelerator pump until you go past 1/3 rd throttle.

To get good highway mileage with a double pumper is to make sure you don't push down on the throttle/gas petal, if you can keep your foot still, you won't be pumping the accelerator pumps and they will get decent mileage but if your are the kind of person who can't drive like this and you like to rap the engine all the time, then I would advise you run a Q-Jet carb as it will help you get better mileage.

There are cars that run a 1050cfm Dominator carb on the street with a sbc 400 and a powerglide transmission with 3.55-3.42 gears out back and they're streetable but mileage sucks. But look out when they hit the nitrous and run low 9s @ 140 plus mph in a quarter mile.

A .040" over 403 will love a 750-850 double pumper IMO so long as you know how to tune it and drive like I explained above.

85cutlass6.6

Thanks for all the info guys, im an currently looking to buy a q jet that came off of a 79 403, $40 but hes out of state and doesnt want to ship

clueless403

is there a specific q-jet that you are looking for I have 2 of them and a rebuild kit that im not going to use. I have no idea what size they are, or how many sizes there are. so with that being said, if you or someone could tell me the numbers to look for to figure out what they are i might be able to give you a deal. 1 was on the 307 i have and the other was in the trunk

85cutlass6.6

@clueless 403
17059553, someone told me this #, if you think its around 750 i'd be interested in it and the rebuild

clueless403

well if i got the right number off the carbs (kinda resembles your number starting 170) 17061824 and 17061829 i have no idea what they are, but i will try and find out

85cutlass6.6

The only thing i could find is that they were used on corvettes? Sbc's

clueless403

yeah i seen 1 said it was for a truck that the guy wanted to sell off his corvette. hopefully someone will chime in and give some expert advice. i did find another set of #s neer the back next to wherethe secondaries are they are close to the same but not 17080259, 17089201

85cutlass6.6

http://www.carbkitsource.com/carbs/kits/CK140.htm check it out they have all the parts numbers on the right side, i think the 17080259 is for 307...

85cutlass6.6

nope, its for 350