[Tom Vaught]

CENTER CARB 1966 421 engine

The 1966 Pontiac Tri-Power Carburetors information, as requested.
(For verification of the Carburetor Calibrations that you have on your 1966 Engines.


I will post the Center Carb: 7026074 info now. Same format, again, from the Rochester Products People
in the way the information is presented by them.

Air Horn Number: 7031588 (1)
Venting: Internal 7007199 Vent Tube
External Venting: Idle Vent
Support: None
Needle Seat: 7026305 Size: .120
Float Valve: 7022779 Pull Clip: 7006474
Float Assembly: 7012028 Spring: None
Fuel Level: .625" at 6.0 psi
Mech. Setting: .594" Drop: 1.97"
(to sharp edge of seam at toe of float)
Pump Assem: 7032280 (synthetic)
RET Spring: 7004597 Size: .025"
DUR Spring: 7011385 Size: .045"
Pump Rod: 7025575 Length 3.06"
Pump Jet: drill (2) Size: .026"
Jet Location: In Cluster
CAP cc/10 strokes: 18.0 - 21.0
Rod Set: .952 from air cleaner flange surface to top of pump rod
Power Piston Assy: 7012266
act spring 7012265 Oz 8 Color (green)
Power Valve Assy: 7011989
Power Rest: 7010144 Size: (.044)
Metering Rod: (blank) Spring: (blank)
Rod Size, Power (blank) Econ: (blank)
Cut-In down at: 11 "Up" at: 8 all in at 6" hg

MM. Jets: 299 cc, 60 degree, 7008660 "B"
7013333 Idle Compensator Assy:
(140 degree (+ - 10 F) Opening Temp

Choke Housing: (2*) (Some of the next 14 lines available for the Choke Description are blank)
Here are the ones with Info:
Valve No: 7033443 Angle: 20 degrees
Cam No: 7020541
Choke Link: 7019524 Length: 2.671"
wo Kick: .143 - .183 Second Step: .090 .100
Vacuum Break: 25 degrees + - 1.5 degrees (.168 - .192)

Float Bowl (Finish) Float Bowl and Body Number: 7031576
Venturi Size: 1-3/16"
Cluster: 7032380 (4*) Boost Size: 1/8
Nozzle: 7020753 rel .014 - .026
Idle Tube: 7011030 "C" Size: .030
Channel Rest: 7009437 Size: .045
Hi-Speed Bleed: drill (2) Size: .028
L.I.A.B: None
Idle Bleed: None
Top Bleed: .039 over idle tube
Side Bleed: .033
Insert: (2) 7008866 (trumpet)
Radial Tubes: (blank) Size: (blank)
Crossover Chan: .125 Main Well Chan: None

Throttle Body Assem: 7031595
Body & Bowl Assem: (blank)
Thr Body No: 7031597 Bore: 1-11/16
Thr Valve: 7025509 Angle 10 degrees
Idle Needle: 7029605 angle: 20 degrees

All drilling info is blank

Port Punch Length: .250 Width: .030
Port Punch Loc: .233 Top Valve Top Slot
Other: 7032290 throttle body gasket
7020778 thr shaft lever assy
7024885 throttle lever
.055 dia hole in thr valve
thr shaft offset .017 - .023

no spark port info

Test Specification 7022221

Min Air: .65/ lbs min Idle Air rate: .95 lbs min
Box Balance 18" Hg - 3" Hg
(Note all 2 BBL carbs are tested at 3" of mercury (TV)

Remarks: 7013333 idle comp assy
140 degrees F + - 10 degrees F opening temp

(1*) 7021007 air horn gasket 7031590 nut - fuel inlet bend pump lever tang to open idle vent
with .020 gage between thr valve & bore on side opposite idle needle.
(2*) 7026095 vacuum break control assy 7026098 remote choke coil assy
(3*) Service Pump Setting 1-21/64 + - 1/64 from top of die cast air horn ring to top of pump rod
(4*) .026 dia hole aspirator to main well bleed
Note: 7031598 vacuum switch assy

date 3-9-1966
Customer 1966 2G Pontiac (Auto) 421 engine A/C Center