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What carby for mild 308


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#1 _holdon_

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Posted 15 June 2010 - 04:02 PM

I have had a bit of a read of the past posts but Im not yet convinced what carb I should run on my 308.

Some back ground info;
Stock 308 with mild cam
Standard inlet and exhaust manifold
LC torana, 5 speed ceilica box, 3.55 banjo diff, electronic ignition
Mainly used as a cruiser and certainly the odd squirt here and there.

I have just finished converting to 308 and I have a Holley 650 DP spreadbore. Just trying it tune it I have noticed the amount of fuel this thing uses. I figured as its only a stock 308 the 650 DP is a overkill am I right?

Is it worth me replacing the holley with a quaddie? Or should I stick with the 650? (the 650 is used I have no idea of its condition)

I noticed on ebay someone is selling reconditioned quadrajets for $280 + postage. Can anyone comment on these?

#2 Gunmetal LH

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Posted 15 June 2010 - 04:14 PM

Can't comment on the quadrajet, never had one. Other people I know swear by them.

I've got a 600 vac secondary on my 253 in the VB and although it guzzles fuel compared to my VN V6 it really isn't that bad on fuel.

It was on there when I got it and I just haven't bothered to play with it or change it even though it is really too big.




I'd say a 650 DP certainly IS overkill.

#3 Lima31

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Posted 15 June 2010 - 04:25 PM

By the time you run a reco kit through the Holley, you might as well have grabbed the quadrajet I guess.

I think a mech secondary is preferable on a light car though, no idea whether the quadrajet is still the better pick.

Edited by Lima31, 15 June 2010 - 04:25 PM.


#4 TerrA LX

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Posted 15 June 2010 - 04:32 PM

650DP spreadbore is a shit carby, these carbs were made for the sales market to be a direct bolt on replacement for the quadrajet, either get a quadrajet or if you have a manual gearbox get a performance carby such as a SQUAREBORE HOLLEY.

Edited by TerrA LX, 15 June 2010 - 04:32 PM.


#5 _oldjohnno_

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Posted 15 June 2010 - 07:39 PM

The 0-1850 has always been a pretty consistent performer on mildish engines.

#6 _holdon_

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Posted 16 June 2010 - 07:56 AM

The 0-1850 has always been a pretty consistent performer on mildish engines.


whats a 0-1850? a model number i take it? of what?

#7 _holdon_

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Posted 16 June 2010 - 10:04 AM

Further to rochesters - what model numbers should i look for and what should i stay away from? I dont need the polution gear if it matters.

#8 sbc57lx

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Posted 16 June 2010 - 10:21 AM

I've tried Holley's ( on 308's ) AND have always gone back to a TUNED Q'JET . just find someone that know how to set one up - should be easy ..

#9 _holdon_

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Posted 16 June 2010 - 11:44 AM

I have a bloke that can and will tune either. The thing is - im not sure whether to keep the 650 or replace it. i dont want to spend $$ on tuning it and then decide to ditch it for something else.

once set up properly - what are the cons with the holley?

#10 _oldjohnno_

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Posted 16 June 2010 - 05:23 PM


The 0-1850 has always been a pretty consistent performer on mildish engines.


whats a 0-1850? a model number i take it? of what?


It's a basic 600cfm square bore Holley with vac. secondaries

#11 _rob350hatch_

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Posted 16 June 2010 - 10:53 PM

650DP spreadbore is a shit carby, these carbs were made for the sales market to be a direct bolt on replacement for the quadrajet, either get a quadrajet or if you have a manual gearbox get a performance carby such as a SQUAREBORE HOLLEY.

yes very true crap crap crap a violent carby the 650 spreadbore diff between the primaries and secondaries on the 650 sb renders it no good for road use .

#12 chrome yella

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Posted 17 June 2010 - 12:19 PM

i ran a 4165 holley 650d/p spredbore for years, i liked them, yes they are violent compared to a Rochie but great fun.
downfalls are fuel compsumption. i couldnt get better than 12mpg and in town about 8mpg, which was better than the 780cfm vac sec holley i had, it only managed 8mpg highway and 4mpg in town. This was 25 years ago when petrol was cheaper tho

i use Rochies now, there the best all rounder money can buy
just get one off a reputable builder.

#13 Redslur

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Posted 17 June 2010 - 12:23 PM

601 or 603 Rochester for sure. Most drivable and reliable for a mild 308.

#14 _oldjohnno_

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Posted 17 June 2010 - 01:14 PM

...downfalls are fuel compsumption. i couldnt get better than 12mpg and in town about 8mpg, which was better than the 780cfm vac sec holley i had, it only managed 8mpg highway and 4mpg in town. This was 25 years ago...


WTF?
25 years ago I was getting 17-18mpg from a 454 with a 780. This was in a 1700kg car with 3.55s..

#15 _holdon_

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Posted 31 January 2011 - 11:01 PM

601 or 603 Rochester for sure. Most drivable and reliable for a mild 308.


Im new to rochesters - there appear to be heaps of differnt models out there....What are the differences with the 601 and 603? looking around and the 603 appears to be more $. Again - its for a mild 308 with manual trans...

#16 Redslur

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Posted 01 February 2011 - 04:28 PM

601 - pre pollution fitted on 308's up until June 1976
602 - pollution model fitted from July 1976 onwards
603 - Fitted to 308's in the VK Comodore range. (may have been the same on the VH 253 but not entirely sure)

I have had all three of them on various mild 308's over the past 20+ years. The 603 is the pick of the bunch and most tunable. The 601 was a good simple carby too where as the 602 was not as good as it was more set up for all the pollution requirements set out in the later ADR 27 revsion. Any of the Rochesters would suit your combo fine.

Edited by Redslur, 01 February 2011 - 04:29 PM.


#17 mr5000

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Posted 01 February 2011 - 04:51 PM

yeah i gotta agree rotchesters all the way they are a fantastic carby and you can get good power out of them they are just a lil bit harder to tune than a holley for some one who is not familiar with them

#18 _nemo355v8_

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Posted 01 February 2011 - 06:00 PM

Go the Quaddie, awesome carb set up right, had one on my little 330 stroker relaced it with a demond 750 and could only get within 1 tenth of the best time with Quaddie.

good on fuel cause your only cruising on the tiny 2 front barrels and have 2 huge second barrels for the fun parts.

#19 _76S.L.R_

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Posted 01 February 2011 - 07:14 PM

I have,I think?? the 603 Rochester on my 308 LX= I borrowed it off my bother years ago and still have it on my car( he now wants it back) from memory he told me it came off of a VK so Im assuming its the 603?,is there serial,no's on the carby's to differentiate them?.

It's been problematic for me though and now is flooding on hot start up,my brother tells me these are renown for this?,anyways I too am now looking for another carby and unsure what to opt for?? my car is pretty mild and just a streeter.
308.
Mild Cam.
Yella Terra Heads.
Elderbrock Performer manifold( port matched).
Turbo 350 Box ( shift kitted)
Standard Torque converter.
Stainless Extractors.

9" diff.

Current have the 603 Rochester,I think? what carby do you guys recomend I should look for?

Edited by 76S.L.R, 01 February 2011 - 07:15 PM.


#20 _TorYoda_

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Posted 01 February 2011 - 07:30 PM

A properly set up 650 spreadbore will work perfectly even on a stocker. I have set up a lot of them over the years with excellent results. I have also had great results with Rochesters.

The simple truth is people will recommend whatever they have had the best experience with. The other simple truth is the Holley can be set up just as well as the Rochester if you have the right guy doing either carb. 1850 vac sec Holley is a great all rounder but once again, correct set up becomes the key factor. Regardless what carb you choose it will be shit if you do not have the right person to set it correctly.

Me personally?, Rather than spand more cash on another carb I would stick with what you have, the 650 DP S'bore, as I know how well they can work when correctly adjusted for the engine. Poor mileage is only a side effect of equally poor setup. I have tuned 1150 dominators on big block chryslers that returned 18mpg. Just because most people (including many 'experts') cannot do it does not mean it cannot be done!

Flooding on old Rochesters is usually due to a permeated float. Over the years the floats degrade and absorb fuel. Once they lose their bouyancy they flood badly..

#21 _holdon_

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Posted 02 February 2011 - 08:00 AM

Thanks for the replys guys. I ended up biting the bullet and getting a rebuilt quaddy. I figured I would save a few 100 bucks by not needing to get this tuned as I would've have to with the Holley (carb rebuilder said it will be 99% right and I will only have to adjust/confirm the mixtures and idle when I get it).

Got the 603 Australian release quaddy too. Pretty happy with the purchase seeing as fuel is tipped to hit $1.50 in Brisbane this month...

#22 Lima31

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Posted 02 February 2011 - 08:58 AM

601 - pre pollution fitted on 308's up until June 1976
602 - pollution model fitted from July 1976 onwards
603 - Fitted to 308's in the VK Comodore range. (may have been the same on the VH 253 but not entirely sure)

I have had all three of them on various mild 308's over the past 20+ years. The 603 is the pick of the bunch and most tunable. The 601 was a good simple carby too where as the 602 was not as good as it was more set up for all the pollution requirements set out in the later ADR 27 revsion. Any of the Rochesters would suit your combo fine.


Were 603s produced in 1974?

There is an evilbayer selling a 603 saying it came off a LH

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=260701779125&ssPageName=STRK:MEWAX:IT

#23 chrome yella

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Posted 02 February 2011 - 09:04 AM


...downfalls are fuel compsumption. i couldnt get better than 12mpg and in town about 8mpg, which was better than the 780cfm vac sec holley i had, it only managed 8mpg highway and 4mpg in town. This was 25 years ago...


WTF?
25 years ago I was getting 17-18mpg from a 454 with a 780. This was in a 1700kg car with 3.55s..

OK did the math, it was 28yrs ago and it was a poorly designed engine by todays/any standards, 337sb chev with big
everything, lousy under 3,500rpm and running a t400 with stock stall,Long open country roads in my area so i used
to open it up often.

#24 LH8VD69

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Posted 02 February 2011 - 11:20 AM

I've used heaps of different carbies over the years and also a huge assortment of tuners and found although the 650 was alot of fun and fantastic when tuned it went out of tune within months. Before anyone says anything once again it was with various tuners over a 7 yr period. I enjoyed it all the same. The 465 although small isnt a bad carbie along with the very commonly used 600 vac. 750 not to bad either. I have to say though if i were you and were just after reasonable economy the Rochester you have bought (if tuned correctly ) is a good choice as i have found they seem to stay in tune alot longer than a holley. The only carbie that compares in this area is my current Edelbrock carbie which is sweeeeet ! Of course these are only my opinions over the last 20 odd years. Goodluck with the Rochie !!




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