This will be the second Q-jet I build since I've discovered Cliff's book, Cliff's great parts, and this forum's great knowledge. First one was a 17059217 for a friend's 400 sbc with mild cam and the results were fantastic.
Now my wife has a 67 Firebird with a factory stock 326 HO 67 Bird which has a factory Carter square bore. The advertised CR for this motor is 10.5, and HP is 285. Only modifications to this car are 1.5/8 4 tube headers, 2.5" flowmaster dual exhaust, and 200r4 transmission with 3.55 rear.
She bought a factory 67 Pontiac intake manifold and I found a 1979 301 carb. I wanted a late model with APT and electric choke provision. Now for the question. I'm having a hard time figuring the recipe for a starting point for the idle and main circuit. Here's what I have measured so far: idle tubes: .033, channel restriction: .044, upper IAB: .070, lower IAB: .071. Main air bleeds are: .074 in air horn and .040 in main body.
Now here's what I've been thinking of doing: leaving idle tube and channel restricion the same, enlarging idle mixutre screw holes a bit. Enlarging lower main air bleed to .070 (from .040) and going with Cliff's full taper .044 rod, not sure of jet starting point as of now.
By the way, this car has no idle air bypass but has passages for it. I was thinking of making it adjustable with home made "jets" out of 10-32 set screws.
One more thing: can I get rid of the rear choke pull off ? The front one seems to do the job of cracking open the choke plate, just don't see the reason for the second one.
Sorry for the long post, and thanks again to everyone on this forum and to Cliff for his great work. Frank.