|
|
|
10-08-2007, 09:13 AM
|
#1 |
|
Account Suspended
Join Date: Sep 2005
Location: Monroe, WA
Posts: 3,815
|
Re: Carb choice for 350
Been posted a million times, but:
CFM = ((CI x RPM)/3456) x VE; VE for a stock engine is around 75% (optimistic). This means for a square bore you don't need the secondaries until 4000 RPM, and you'd have to turn 8K to need more than 600 CFM  Another vote for a good overhaul on your existing Q-Jet. They're great carbs and typically just need a little TLC. The only problem is tuneability - there just isn't great availability on jets and rods any more  After the Q-Jet, any good vacuum secondary carb of 600-650 CFM is a good choice.
Last edited by Billla; 10-08-2007 at 09:13 AM. |
|
|
|
10-08-2007, 10:26 AM
|
#2 |
|
Registered User
Join Date: Dec 2006
Location: Earth
Posts: 239
|
Re: Carb choice for 350
I had a local guy rebuild my old Q-jet, it was original on the truck with 230,000kms......
Anyway, I had him tweek it for towing....so he put bigger jets, shorter secondary rods, and removed the Secondary brake mechanism, and replaced everything in the carb.....bushings, float, etc... All in all it was $300 cash, and all I had to set was the high, and low idle speeds on the truck, and I was off to the races. If you were up here in Ontario, i'd give you his number.... Just my 2 cents, the Qjets are excellent carbs if there tuned/running right. It's the guys that tweek them in there driveways, and have no idea what there doing in the first place that cause there own drivability problems, and blame it on GM, when it's there own problem Duro
__________________
-1986 K10 LWB, 350 HD,TH400 3.08, 30 spline 10 bolt, with an Auburn Posi, 31" tires All original, second owner truck -1979 Monte Carlo, 350, 200r4, 3.73 posi -1987 GT T-top Mustang - slow moving project |
|
|
|
|
10-08-2007, 03:44 PM
|
#3 |
|
Excelsior, You Fathead.
Join Date: Jun 2004
Location: Valparaiso, In
Posts: 937
|
Re: Carb choice for 350
I'll take the qjet if you trash it, I'm starting a collection. I'm actually thinking about doing this a little on the side.
__________________
Go Navy. The Sea Is Ours. Budget 350 Build http://67-72chevytrucks.com/vboard/s...38#post2264638 |
|
|
|
|
10-09-2007, 03:03 AM
|
#4 |
|
Senior Member
Join Date: Aug 2004
Location: Everett, WA
Posts: 2,316
|
Re: Carb choice for 350
<slight derail>
Alright, follow me if you can. My '86 lwb had the original 305 in it when I bought it. Had carb rebuilt just after I bought the truck. Replaced the engine shortly after with a 350 with an "RV" cam. Since the carb was rebuilt for the 305 is it a hinderence on the 350? My 86 swb had the original 350 in it when I bought it. I have installed a low mile 305 in the truck. Is the carb from the 350 going to be a hinderance on the 305? Should I swap the carbs around provided they are the same as far as emissions and electrical connections go? </slight derail>
__________________
2009 Honda Fit CfC (bsf 44.9 mpg) 2000 Tahoe Limited 1991 GMC CrewCab Dually 2wd, will end up swb, not dually and replace CCswb below 1991 GMC CrewCab Dually 4x4, just going to fix things up for now 1982/1989 K5/GMC Jimmy 2wd 1987 GMC 1/2 ton swb 2wd Crew (sold) |
|
|
|
|
10-10-2007, 05:13 PM
|
#5 |
|
Registered User
Join Date: Jul 2005
Location: Riverside CA
Posts: 860
|
Re: Carb choice for 350
i bought a rebuilt quadrajunk from a rebuild shop for about 90 bucks after core and it was the nicest running truck i've had. i made sure to get one with a manual choke and it doesnt get cold enough in ca for me to ever use the choke. plus i think the quadrajets handle angles a little better than edelbrocks.
|
|
|
|
|
10-10-2007, 08:21 PM
|
#6 |
|
The master of disaster
Join Date: Nov 2006
Location: Warsaw Texas
Posts: 249
|
Re: Carb choice for 350
From personal experiece id have to say an edelbrock 650cfm proformer carb better in my books
|
|
|
|
 |
| Bookmarks |
| Thread Tools | |
| Display Modes | |
|
|
Hybrid Mode
