Hello i have a 1967 camaro with a modified 2 bolt 350 producing about 350 hp give or take a few horses. I need a new carb and was wondering whether i should get a jet performance products stage 2 quadrajet or a holley street avenger 650 double pumper. Can anyone tell me the advantages/disadvantages or each? Will the holley use much more gas then the quadrajet? The car will be used mostly for driving but will be taken to the strip occasionally. If neither of these carbs are adequate can you suggest anything else? thanks for your time,
04-17-2007 10:08 PM
Get the Holley, or an Edelbrock. Quadrajets (aka Quadrajunks) are hell to tune. My buddy loves them, but he also loves to spend forever adjusting them.
04-17-2007 10:10 PM
Jet q-jet are very good carbs,if you give them your engine info the can makeup a carb for you setup. Holleys are good also
04-17-2007 11:14 PM
Colin, to start with the Holley Street Avenger is not a double pumper, its a 570 or 670 (for your application) elec. choke, vacuum secondary carb, you don't want a DP for the street. The quadrajet is an xlnt carb and not "hell to tune" if you take your time and know what you're doing. Either carb will work for you IF tuned properly. Another source for quadrajets is "I Five Components" (800) 526-9952. They will build you a vehicle specific carb for around $280....but you need to know your engine specs. Don't just tell them its got around 350 hp, most guys way over estimate their engines hp. If you're looking for mileage and who isn't I'd get the q-jet.
04-18-2007 06:12 AM
I agree with 327nut, the QJ if set up properly will outperform the Holley Street Avenger (are all single pumpers) both in fuel economy and WOT. Off idle response on the QJ is vastly superior to the Holley.
04-18-2007 04:44 PM
the smaller primarys on the q jet will give u nice crisp acceleration, and if tuned properly awesome idle and street performance. where as the holley you will lose some drivability. you may get a bit more power from the holley just because its easier to tune but if u take your time and get a detailed book, u'll be happy you chose the quad.
04-18-2007 04:59 PM
the Q jet will give you better mileage Provided you stay out of the back barrels & there is no waiting time as the Holly for the Vacuum secondaries to open.