IS it possible? There`s alot of vaccum lines and stuff on the stock carb that wouldn`t be on the holly. This is an 86 IROC.

 

You might also notice there are a few wires pluged into the stock carb by the accelerator pump I believe also. That's for the computer that also controls the distributor. You may run into problems by-passing all that with the Holley. To run the holley you will probably need to run an older style non-computer HEI distributor and eleiminate the use of the computer. Or to keep the Q-jet and gain performance you could change the secondary metering rods and hanger. I get the rods from summit. They cost about 5 bucks for a set. The hangers are about that also. Pretty cheap.

I would love to run a comparison some day. I am not convinced the holley will out perform. With a 750 cfm capacity and the ability to make metering rod changeds and tension changes on the vaccuum secondaries I beleive the Q-jet is just as capable on a daily driver/weekend drag racer.

 

I'm no carb expert, but when I've seen comparisions the holley and stock rochester all seem to make identical horsepower numbers. It's all about proper tuning and proper cfm selection.

 

The Q-jet is a great carb if you know how to tune it. Personally, I don't....I like the Edelbrock design better, it's simple and therefore reliable. If you decide to dump the Q-jet you will have to have a non-computer distributor, which means and old HEI unit out of any given SBC from any given junkyard. Prolly run ya $40-50.

And as far as the vac lines....if you start tearin out the emissions control equipment you'll eliminate about half of them. Not sure if that's an option where you live, but it's an idea.

 

Then there is the problem of the torque converter lockup, which is controlled by the ECM on the cc QJet cars. You can get a switch to wire in so you can flip it in on the hghway.

I agree, though, the QJet is a terrific carb. If you have the computer controlled one go to www.thirdgen.org and look in their tech articles for info on tuning them. Man, they run great and will pay for themselves in saved fuel over any Edelbrock or Holley.