I'm currently getting my engine rebuilt and buying up goodies while I can. My question is: How do I know if my stock q-jet needs rebuilding or replacing? I found a holley 750 cfm for $175. Do those work well with a 350?
If you plan to keep your Q jet then send it to Everyday Performance for a rebuild... It is not worth messing with an old carb on a new engine. The Holley is ok if you take the time to re-jet it using an air fuel meter.
The stock Q-Jet for your engine went through thousands of hours of testing and calibration by the RPD engineers to get it optimal for street use on your particular engine, drivetrain, and option package. If you're getting the engine rebuilt to factory specs, keep the Q-Jet and refurbish it. If you're going for modified pistons, rods, heads, cam & intake on that engine, then deviating from the stock carb would be applicable.
It is also worth mentioning 2 things: 1. If you care at all about fuel mileage then use the stock Q jet with a rebuild. The Q jet will get better fuel mileage. I have gotten as good as 22 US MPG with one. 2. If you plan to use a Holley square bore carb (4 equal sized throttle blades), then you will need an adapter to go from the stock intake to the Holley. This does not work the best... If you do want to go with a Holley square bore carb then buy a TA intake as it is better suited for that application.
Thanks for the replies. I have a TA intake, TA212 cam, headers, bored .030 over, 10:1 pistons, shaved heads, and a port matching job. Would the Q-jet hinder performance any? Not concerned with gas milage as this is my toy...not daily driver. What carb would you guys use for that sort of set-up? I know nothing about carbs, "rejetting" is gibbledeegosh to me. I imagine I can look up the "how to videos" on youtube.
If you are even thinking "is my carb bad" then its worth at least cleanup and regasket. stock rebuilt will get you the best gas mileage recalibration and rejetting gets you increased throttle response and power at the expense of gas mileage.
I think you would be very happy with a properly built Q-Jet given this engine combination. It would in no way hinder performance, and would actually provide crisper throttle response than a Holley or similar carb at normal cruising RPM levels.
X2 -- plus it's an easy bolt on and go.. no fuss no muss.. factory connections are already there.. Send it to one of the guys on the boards here, It'll be done right... or their reputation suffers and we never let em hear the end of it... :laugh:
"Thanks for the replies. I have a TA intake, TA212 cam, headers, bored .030 over, 10:1 pistons, shaved heads, and a port matching job. Would the Q-jet hinder performance any? Not concerned with gas milage as this is my toy...not daily driver. What carb would you guys use for that sort of set-up?" A properly set up factory q-jet will much just as much as, if not more power than anything else you can find, and get better fuel economy as well. A few years ago we were doing some dyno testing for some magazine articles that ended up in HPP and Popular Hot Roddings Engine Masters edition. Toward the end of the dyno session the representative from the magazines was poking around in the dyno room and picked up a huge HP950 Holley carb, and asked us if we could do a couple of pulls against my factory q-jet to "see how much power my engine would really make?" I figured I was in trouble, and have to buy lunch that day for everyone. The big Holley made 2 less HP than my Q-jet on the very next pull.....and.....not one article ever came out of that part of the testing......wonder why?.......Cliff
That seals the deal for me. Thanks! Didn't think about the connections. The old Q-jet it is then. Thanks! Thanks everyone.
