RPMS Posted September 8, 2003 Share Posted September 8, 2003 Gentlemen, I've got two carbs sitting here in front of me: A Holley 4165 and a Quadrajet Both are older units with automatic chokes, and both need to be rebuilt. The Holley came off the 1971 Chevelle that's disassembled in my sister's barn, and the Quadrajet is a non-electronic one off a late 1970's Chevy truck. Other than the need to be rebuilt, they're in fairly good condition and appear serviceable. I've got a mild Chevy 350 engine with an Edelbrock Performer intake driving a 700R4 tranny with a stock torque converter. Driveability is preferable to ultimate HP, but I'm not willing to lose too many horses in the process. So. With all that information, which carb should I spend my time/money rebuilding? Which one will give better performance/driveability/economy? Thanks, Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted September 8, 2003 Share Posted September 8, 2003 What Q-Jet? Is it a spreadbore? If it is I would definitely pick that. They are excellent for drivability as well as tons of power. You can run around on the primaries and get good mileage, then pound it and open the secondaries when you want to haul a$$! I have a Q-Jet with a performer manifold on the 350 in my truck and it just plain ROCKS. BTW, if you decide not to go Q-Jet I am pretty sure I could find a good home for it Quote Link to comment Share on other sites More sharing options...
Guest oldZguy Posted September 8, 2003 Share Posted September 8, 2003 Growing up during the days of the QJ the first thing we ever did was get rid of it and put on a Holley, I would go with the Holley myself, besides you probably won't be able to bolt on the QJ without an adapter plate since your aftermarket intake is probably made for a squarebore carb like the Holley. If you go with the QJ and need an adapter plate I have one in my box of antique speed parts you can have. Lance Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted September 8, 2003 Share Posted September 8, 2003 Isnt the Holley 4165 a Double-Guzzler? Err, Double-Pumper Wouldnt be my choice for mileage. Also as a side-note, it doesnt take much to swap out a carb. Why not run each one for a few days or a week and see which you like best? If you do decide you prefer the Holley and want to sell the Q-Jet, can I have dibs? Quote Link to comment Share on other sites More sharing options...
RPMS Posted September 8, 2003 Author Share Posted September 8, 2003 Hey, guys. Thanks for the offer of the adapter Lance, but it doesn't look like I'll need it. Both of the carbs are spreadbore, and the intake will accept either of them thanks to a dual bolt pattern on it. The Holley has only one accelerator pump on it, so I don't think this one's a double pumper. The info I've found on the web seems to point to the Q-jet being a better overall choice once it's been tuned and slightly modified, but until those modifications are made, the Holley is better. I also notice that Q-jet rebuild parts are double the cost of Holley's, and there aren't nearly as many aftermarket parts available for it. Comments? Quote Link to comment Share on other sites More sharing options...
Guest Aaron Posted September 8, 2003 Share Posted September 8, 2003 My dad us using a QJet on his car we are bringing to SEZS this weekend. He got some parts from a guy in Birmingham, AL, that specializes in QJs, and has been featured in several magazines. I can put you in touch with him if you are interested. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted September 8, 2003 Share Posted September 8, 2003 I have a friend who's running Qjet on 455 Pontiac and he makes it work. Except running little lean on top rpm. He dynoed almost 400WRHP with it. And 20mpg. (with double overdrive 6 speed) Quote Link to comment Share on other sites More sharing options...
Guest Aaron Posted September 8, 2003 Share Posted September 8, 2003 Yo, the guy that my dad knows said that is the common issue with the QJ. He said the carb literally runs out of fuel in the bowls. There are apearantly some holes that can be drilled out in the carb that will correct or help the problem. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted September 9, 2003 Share Posted September 9, 2003 I have heard of drilling a hole thing too. I think my freind done that on his. But you know Qjet was never meant to support that kind of HP. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted September 9, 2003 Share Posted September 9, 2003 Yo, the guy that my dad knows said that is the common issue with the QJ. He said the carb literally runs out of fuel in the bowls. There are apearantly some holes that can be drilled out in the carb that will correct or help the problem. Um. Normally turning up the fuel pressure is a good fix for that Quote Link to comment Share on other sites More sharing options...
Guest Perry Posted October 9, 2003 Share Posted October 9, 2003 Just slap the one on that looks to be the best shape then drive it to the book store and get David Vizard's intake & carbs book. It has instructions for a lot of carb mods on both QJ and Holley, plus it will give you an idea of the advantages of each type and a very good lesson on the inner workings of carbs that will help a lot when tuning. In general I think what you said is correct. QJ takes a bit more work and money but can perform better on a street machine. Holley works well out of the box but won't be as good as a tweaked QJ when driveability/mileage is a concern. If you read the book and get into carb theory then build the one you want, otherwise flip a coin, slap it on and you'll probably be happy with it. Perry Quote Link to comment Share on other sites More sharing options...
Tim240z Posted October 9, 2003 Share Posted October 9, 2003 I have 2 Q-Jets sitting in my garage off of 69-71 chevy 350 trucks. Both worked well when i took them off 3 years ago. Anyone want them? I put a 750 DP holley on my truck. Tim Quote Link to comment Share on other sites More sharing options...
johnc Posted October 9, 2003 Share Posted October 9, 2003 If you're building a sleeper, run the QJet. Way back in the late 1970s I had John Lingenfelter (yes, the same guy) blue print an 800CFM QJet for my 1966 455 GTO. The car run 13.2s all day, every day with the QJet, stock air cleaner, cast iron intake manifold, cast iron exhaust manifolds, etc. and I won lots of money on the street with that car. Told everyone that car had a 389 and no one ever questioned that statement. Quote Link to comment Share on other sites More sharing options...
Guest BigWhyteDude Posted October 9, 2003 Share Posted October 9, 2003 i wish i was born just before the muscle car erra Quote Link to comment Share on other sites More sharing options...
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