What's the right carb with my engine setup?

Street Demon 625 cfm, if you want shiny new. It is a 3 barrel heavily based off the Carter Thermoquad the Carter AFB's replacement, which is the Edelbrock carb. Both carbs will be rich out of box, they are set up for 9+ to 1 350+ ci with bigger than stock cams. One guy put the Street Demon on a 8 to 1 350, got 14 mpg. After leaning it out, 19 mpg. It is very similar to Qjet, 20+ should be no problem with a properly tuned Street Demon. A stock late 70's 305 or 350 Qjet with the right linkage will be very close for your stock 305. I assume that intake is equal to the Performer RPM?

slowestmonte said:

Wow, I didn't realize you could get upwards of 25 with a rochester. Maybe I'll have to make the old manifold work and get a pre computer rochester.

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I have a 5 speed with a .67 5th gear and 3.08 rear end. I kept it 60 to 65 mph for a 3 hour drive and I got 26.8 mpg.

pontiacgp said:

for a stock 305 a 500 cfm would work fine. A 305 at 6000 rpm needs less than a 500 cfm carb. When we ran in the super stock division we used the GM 602 crate which is a 350 and we were limited to a holley 500 cfm 2 barrel. The chip we had to run was a 6200 rpm and that carb never ran out of gas or power. That holley was a race version but it was only a 500 cfm. That being said I do not like holley carbs for the street. I have a Quadrajet with an adapter to fit my carb on a squarebore vortec intake. With my 355 I can get over 25 mph on the highway.

http://www.carburetion.com/calc.asp

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25mph huh? I average 70 myself.

MrSony said:

25mph huh? I average 70 myself.

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70?....you have a quadrajet on a moped?

pontiacgp said:

70?....you have a quadrajet on a moped?

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mph.

my 'stock' 87 SS is rated 17/24mpg. I can 'hype-mile'* it to 24.5mpg at 62 mph

* flat ground, A/C off, windows up.

If I was in your (situation) car I'd go with a Holley 0-9895

slowestmonte said:

Wow, I didn't realize you could get upwards of 25 with a rochester. Maybe I'll have to make the old manifold work and get a pre computer rochester.

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Dont hold your breath

StreetStock#72 said:

my 'stock' 87 SS is rated 17/24mpg. I can 'hype-mile'* it to 24.5mpg at 62 mph

* flat ground, A/C off, windows up.

If I was in your (situation) car I'd go with a Holley 0-9895

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Wont work with his intake

MrSony said:

mph.

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what are your revs at 70mph

pontiacgp said:

what are your revs at 70mph

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It was a joke man. You put 25mph instead of mpg.