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Buick Stage I Chart

  1. Stage I, Valve Train Package
    Part Group Part No.
    Camshaft - Stage I 0.519 1383853
    Pushrod, tubular 0.426 1383852
    Valve spring and damper assembly (272 lbs.) 0.303 1383851
    Spring, oil pump (60 lbs.) 1.609 1383854
  2. Stage II,
    Part Group Part No.
    Camshaft - Stage II (not recommended for the street) 0.519 1385557
    Valve train and damper assembly 0.303 1383851
    Pushrod, tubular 0.426 1383852
    Spring, oil pump (60 lbs.) 1.609 1383854
  3. Piston and Pin Assemblies (forged aluminum, 11.0:1 comp.)
    Part Group Part No.
    Piston and Pin, (400 cid) 0.629 1394179
    Piston and Pin, (430 cid) 0.629 1394179
    Note: Recommended running clearance of these pistons is .006-.0010-inch. (.008-.012 wide open throttle applications.) Chrome piston pins are to be installed in pistons by heating small end of rods to approximately 450 degrees.
  4. Intake manifold gasket, Group 3.270, Part No. 1383831 (blocked heat riser)
  5. Connecting Rod Bearings (.001-inch oversize to increase clearance without re grinding crank. Running clearance should be .002-.0025.)
    Part Group Part No.
    Connecting rod bearings (std.) 0.616 5468714
    Connecting rod bearings (+.001) 0.616 5468713
  6. Main Bearings (Fully grooved for increased lubrication. Use in No. 2, 3 thrust and 4 locations only. Running clearance is .0011-.0015 maximum.
    Part Group Part No.
    No. 2, 4 Main Std. 0.096 5469067
    No. 2, 4 Main +.001 0.096 5469066
    No. 2, 4 Main +.002 0.096 5469065
    No. 3, Thrust Std. 0.101 5469064
    No. 3, Thrust +.001 0.101 5469063
    No. 3, Thrust +.002 0.101 5469062
  7. Metering Rods, (6% richer)
    Part Group Part No.
    rod, metering 3.802 7034822
  8. Low-tension piston rings (Use with either std. or optional forged pistons.)
    Part Group Part No.
    Piston rings 400 cid 0.643 1394202
    Piston rings 430 cid 0.643 1394203
  9. Spark Plugs - AC 40TS or 42TS
  10. Exhaust headers: Recommended 2 1/4 inch diameter, individual pipes, 36 - 40 inches in length.
  11. General: Maintain minimum of 4 1/2 psi fuel pressure at carburetor. Maintain oil level 1 quart low to prevent foaming.
We had to add this GREAT bit of info. These are the specs for a Stage I cam measured in the conventional format!
Intake
Lift
Exhaust
Lift
Intake
Duration
Exhaust
Duration
Centerline
.415"
.445"
210°
222°
110°
These measurements are not G.M.! They are the original cam measure to conventional industry standards
This is all we have for Stage II cam specs.
Intake
Lift
Exhaust
Lift
Advertised
Intake
Duration
Advertised
Exhaust
Duration
Intake
open/close
Exhaust
open/close
.455"
.480"
340°
360°
52°/108°
112°/68°
These measurements are G.M.!
They are from GS-X-Tra, (Sept./Oct. '82)
Stage I Head Casting Numbers
Head Cast # Year Displacement
1240150 1970 455
1240146 1971 455
1238530 1972 455
1242002 1973-74 455
Stage I heads are the same as regular production heads with the addition of larger valves and firmer springs. The OE part numbers are: intake - 234604, exhaust - 234605, springs - 1383851
 STAGE I
 PART NUMBER  DESCRIPTION
 1231109  cylinder heads
 1383853   camshaft
Intake
Lift
Exhaust
Lift
Intake
Duration
Exhaust
Duration
Centerline
0.406"
0.441"
316°
340°
115° (some with 113° of overlap exist)
 1383851  272-pound valve spring and damper assembly
 1383852  tubular pushrods
 1383854  60-pound oil pump regulator spring
 7029246  Rochester Quadrajet
 6470098  heavy-duty fuel pump with 6 to 8 p.s.i.
 1112016  distributor
 1394440
1394348
 Wildcat mufflers 2-1/4-inch dual exhaust
 3017258  heavy-duty radiator
 1245632  special water pump fan clutch
 1239013  seven-blade fan
   Higher stall speed and modified governor in automatic transmissions
   Positive traction rear axle
   3.64:1 rear axle ratio (on cars without air conditioning; 3.42 on cars with)
   Dress-up kit, including monograms, valve covers and air cleaner lid
 STAGE II
 PART NUMBER  DESCRIPTION
 1385557  Cam Shaft
Intake
Lift
Exhaust
Lift
Intake
Duration
Exhaust
Duration
Centerline
0.455"
0.480"
340°
360°
120°
 1394179  11:1 compression ratio flattop pistons
 1394202  low-tension piston rings
 1383831  intake manifold gaskets
 7034822  secondary metering rods
   Edelbrock B4B aluminum intake manifold
   Holley 850 carburetor
   Mickey Thompson Super Scavenger tubular headers
   4.78:1 rear axle ratio