Hello All,
First time posting and rebuilding a Quadrajet.
I would like start off by saying thank you Cliff for taking the time and trouble to pass on your wealth of knowledge and expertise that has taken many years and untold hours of r/d to gain.
I have a 1973 Suburban ¾ ton 4x4, 4l80 and 411 gears that I have a fresh 383 motor for.
This build is for good drivability with torque in mind for the heavy Suburban and towing.
Motor is .040 over with Summit vortec heads #151124. Int. 1.94 exh. 1.50, 67cc chamber 175 cc runner.
Cam is a Mike Joans flat tappet, int: 212 exh: 220.@.050 Net lift, int: .480 exh: .465 LC: 112 rocker arm 1.6 int. 1.5 exh.
Block is decked to 0 with .039 head gasket
Compression is calculated at 9.5:1
I have a Quadrajet part # 17057504, this carb looks to be in original condition, has no wear in the throttle shafts and was fairly clean inside.
I spoke to Cliff on the phone and have received a rebuild kit, primary rod #44L secondary rods D/A with 75 main jets, orange/red power piston spring.
Question about the #44L rods, from what I understand from reading through the book and on this forum ATP carbs use a tapered rod with a .026 tip. These rods have a .026 tip and have a diameter of .044 at the top but I am only measuring about .001 of taper before it drops down to the .026 diameter, should they be fully tapered from .044 to .026?
I have read Cliffs book a several times and used the recipe #1 for this rebuild.
Idle tube: .36
Idle channel restrictions: .046
Lower idle air bleed: .070
Upper idle air bleed: .070
Accelerator pump discharge: .026
Main air bleed (main body): .070
Main air bleed (air horn): .070
Main well bleed tubes: .036
Main jet: 75
Primary metering rod: 44L
Fuel inlet seat: .125
Float level: .250
Secondary POE well restrictions: .040
Secondary POE restrictions (above air flap): .050
Secondary hanger: G
Secondary metering rods: DA
Air flap open distance: 1.300
Choke pull off: 3 sec.
Idle mixture screw holes: .090
ATP # of turns from seating: ??
Idle mixture screws: 4.5 turns out
Idle bypass air: .105
This carb had the large .120 main air bleeds in the air horn and main body, I have reduced these to the .070 to stay in line with recommended in recipe #1
It also has the idle bypass air in the baseplate, it measures .105. The book mentions drilling these to minimum .125 I need clarification on this recommendation.
Also, when I took the carb apart to clean it, I failed to record the # of turns out the APT was, I have read in some posts that a good starting point is 3-4 turns out from bottoming. Is this accurate?
I would like to try and get the carb as dialed in as possible so it will fire up and run to break in the flat tappet cam. Then I can do the fine tuning.
Any advice/recommendations for accomplishing this would be greatly appreciated.
Also, I need a distributor for this motor.
I have a GM HEI distributor that came from a 1983 truck but has had the center football & weights replaced with aftermarket advance kit. I know that most if not all aftermarket kits are problematic.
Anyone have advice/ideas on what would be a good set of weights and football to get this distributor to work for the initial startup and cam break-in? and where to source them.
Thank you
