150 cu in Four-Cylinder
and
All In-Line Six-Cylinder Engines



Torque Specifications
General

Four-Cylinder Six-Cylinder
Engine Block Engine Block
Pistons and Rings Pistons and Rings
Crankshaft and Flywheel Crankshaft and Flywheel
Cylinder Head and Valve Train Cylinder Head and Valve Train
Oil Pump Oil Pump
Oversize & Undersize Code Letter Definition Oversize & Undersize Code Letter Definition

General
Displacement
Six-Cylinder232 or 258 cu in
Four-Cylinder150 cu in
Bore and Stroke
150 cu in engine3.876 x 3.188 in
232 cu in engine3.750 x 3.5 in
258 cu in engine3.750 x 3.895 in
Oil Pressure
600 rpm13 psi
Above 1600 rpm37 to 75 psi
Firing Order
Four-Cylinder1-3-4-2
Six-Cylinder1-5-3-6-2-4

Four-Cylinder Engine

Engine Block
Cylinder Bore
Diameter3.8751 to 3.8755 in
Taper Limit0.001 in
Out-of-Round Limit0.001 in
Deck Warpage Limit0.002 in over 6 in

Pistons and Rings
Piston-to-Bore Clearance
Standard0.0009 to 0.0017 in
Preferred0.0012 to 0.0013 in
Piston Ring Side Clearance
Compression
Standard0.0017 to 0.0032 in
Preferred0.0017 in
Oil Control
Standard0.001 to 00008 in
Preferred0.003 in
Piston Ring End Gap
Compression0.010 to 0.02 in
Oil Control0.010 to 0.025 in

Crankshaft
Main Journal
Diameter2.4996 to 2.5001 in
Taper Limit0.0005 in
Out of Round Limit0.0005 in
Main Bearing Oil Clearance
Standard0.001 to 0.0025 in
Preferred0.002 in
Connecting Rod Journal
Diameter2.0934 to 2.0955 in
Taper Limit0.0005 in
Out-of-Round0.0005 in
Connecting Rod Bearing Oil Clearance
Standard0.001 to 0.003 in
Preferred0.0015 to 0.002 in
Connecting Rod End Play0.010 to 0.0019 in
Crankshaft End Play0.0015 to 0.0065 in

Camshaft
Bearing Journal Diameter
Number 12.029 to 2.030 in
Number 22.019 to 2.020 in
Number 32.009 to 2.010 in
Number 41.999 to 2.000 in
Bearing Oil Clearance0.001 to 0.003 in
Lobe Lift0.265 in
End PlayZero (engine operating)

Cylinder Head and Valve Train
Head Warpage Limit0.002 in over 6 in
Intake Valve Seat Angle44.5
Exhaust Valve Seat Angle44.5
Intake Valve Seat Width0.040 to 0.060 in
Valve Seat Runout Limit0.0025 in
Valve Guide Inside Diameter0.313 to 0.314 in
Intake Valve Face Angle44
Exhaust Valve Face Angle44
Valve Margin Width1/32 in minimum
Valve Stem Diameter0.311 to 0.312 in
Valve Stem-to-Guide Clearance0.001 to 0.003 in
Valve Spring Free Length1.82 in
Lifter/Tappet TypeHydraulic
Valve Lash AdjustmentZero
Lifter Bore Diameter0.9055 to 0.9065 in
Lifter Diameter0.904 to 0.9045 in
Lifter-to-Bore Clearance0.001 to 0.0025 in
Pushrod Diameter0.312 to 0.315 in
Pushrod Length9.640 to 9.660 in

Oversize and Undersize Component Code Letter Definition
Code Letter
BAll cylinder bores0.010 in oversize
MAll crankshaft main bearing journals0.010 in undersize
PAll connecting rod bearing journals0.010 in undersize
CAll camshaft bearing bores0.010 in oversize

Six-Cylinder Engine

Engine Block
Cylinder Bore
Diameter3.7501 to 3.7533 in
Taper Limit
1972 through 19810.005 in
1982 and later0.001 in
Out-of-Round Limit
1972 through19810.003 in
1982 and later0.001 in
Deck Warpage Limit0.006 in max.

Pistons and Rings
Piston-to-Cylinder
Standard0.0009 to 0.0017 in
Preferred0.0012 to 0.0013 in
Piston Ring Side Clearance
1972 through 1980
Compression (standard)0.0015 to 0.003 in
Compression (preferred)0.0015 in
Oil Control (standard)0.001 to 0.008 in
Oil Control (preferred)0.003 in
1981 and Later
Compression (standard)0.0017 to 0.0032 in
Compression (preferred)0.0017 in
Oil Control (standard)0.001 to 0.008 in
Oil Control (preferred)0.003 in
Piston Ring End Gap
Compression (all)0.010 to 0.020 in
Oil Control
1972 and 1973 only0.015 to 0.055 in
All others0.010 to 0.025 in
Piston Pin Diameter0.9304 to 0.9309 in
Piston Pin-to-Piston Clearance
Standard0.0003 to 0.0005 in
Preferred0.0005 in

Crankshaft
Main Journal
Diameter
1972 through 19812.4986 to 2.5001 in
1982 and Later2.4996 to 2.5001 in
Taper Limit0.0005 in
Out-of-Round Limit0.0005 in
Main Bearing Oil Clearance
1972 and 19730.001 to 0.002 in
1974 through 1980
Standard0.001 to 0.003 in
Preferred0.0025 in
1981 and Later
Standard0.001 to 0.0025 in
Preferred0.002 in
Connecting Rod Journal
Diameter2.0934 to 2.0955 in
Taper Limit0.005 in
Out-of-Round0.0005 in
Connecting Rod Bearing Oil Clearance
1972 and 19730.001 to 0.002 in
1974 and 1975
Standard0.001 to 0.003 in
Preferred0.0025 in
1976 through 1980
Standard0.001 to 0.0025 in
Preferred0.0015 to 0.002 in
1981 and Later
Standard0.001 to 0.003 in
Preferred0.0015 to 0.002 in
Connecting Rod End Play
19720.008 to 0.010 in
1973 through 19800.005 to 0.014 in
1981 and Later0.010 to 0.019 in
Crankshaft End Play0.0015 to 0.0065 in

Camshaft
Bearing Journal Diameter
Number 12.029 to 2.030 in
Number 22.019 to 2.020 in
Number 32.009 to 2.010 in
Number 41.999 to 2.000 in
Bearing Oil Clearance0.001 to 0.003 in
Lobe Lift
1972 through 19740.254 in
1975 and 19760.232 in
1977 through 1979
232/258 with 1 bbl. carb0.232 in
258 with 2 bbl.carb0.248 in
19800.248 in
1981 and later0.253 in
End PlayZero (engine operating)

Cylinder Head and Valve Train
Head Warpage Limit0.006 in max.
Intake Valve Seat Angle30
Exhaust Valve Seat Angle44.5
Intake Valve Seat Width0.040 to 0.060 in
Exhaust Valve Seat Width0.040 to 0.060 in
Valve Seat Runout Limit0.0025 in
Valve Guide Inside Diameter0.3735 to 0.3745 in
Intake Valve Face Angle29
Exhaust Valve Face Angle44
Valve Margin Width1.32 in min.
Valve Stem Diameter0.3715 ti 0.3725 in
Valve Stem-to-guide Clearance0.001 to 0.003 in
Valve Spring Free Length
1972 and 1973Not available
1974 through 1976
With Rotators2.00 in (approx.)
Without Rotators2.234 in (approx.)
1977
258 2 bbl. only1.987 in (approx.)
All others2.234 in (approx.)
1978 and Later1.99 in (approx.)
Lifter/Tappet TypeHydraulic
Valve Lash AdjustmentZero
Lifter Bore Diameter
1972 and 1973Not available
1974 throug 19800.905 to 0.906 in
1981 and Later0.9055 to 09.065 in
Lifter Diameter
1972 and 1973Not available
1974 through 19830.904 to 0.9045 in
Lifter-to-Bore Clearance
1972 and 1973Not available
1974 through 19800.001 to 0.002 in
1981 and Later0.001 to 0.0025 in
Pushrod Diameter
1972, 1973 and 1975Not available
19740.294 to 0.303 in
1976 through 19800.12 to 0.313 in
1981 and Later0.312 to 0.315 in
Pushrod Length
1972, 1973 and 1975Not available
19749.656 to 9.666 in
19769.595 to 9.615 in
1977 through 19809.640 to 9.660 in
1981 and Later9.710 to 9.730 in

Oil Pump
Gear-to-Body Clearance
1972 through 19800.0005 to 0.0025 in
1981 and Later0.002 to 0.004 in
Gear End Clearance
1972 through 1976 and 1981 through 19860.002 to 0.006 in
1977 through 19800.002 to 0.008 in

Oversize and Undersize Component Code Letter Definition
Code Letter
BAll Cylinder Bores0.010 in oversize
MAll Crankshaft Main Bearing Journals0.010 in undersize
PAll Connecting Rod Bearing Journals0.010 in undersize
CAll Camshaft Bearing Bores0.010 in oversize
All Models

Torque SpecificationsFT-Lbs
Camshaft Sprocket Bolts45 to 55
Carburetor Mounting Nuts12 to 15
Connecting Rod Cap Nuts33
Cylinder Head Bolts
197280 to 85
1973 through 1980105
1981 and Later85
Crankshaft Pulley-to-Damper Bolts20 to 25
Exhaust Manifold Bolts20 to 25
Fan and Hub Assembly Bolts15 to 25
Driveplate-to-Torque Converter Bolts20 to 25
Flywheel/Driveplate-to-Crankshaft Bolts100 to 110
Intake Manifold Bolts20 to 25
Main Bearing Cap Bolts80
Oil Pump Cover Bolts6
Oil Pump Mounting Bolts
Short8 to 12
Long15 to 18
Oil Pan Bolts
1/4 x 205 to 9
5/16 x 1810 to 13
Bridged Rocker Pivot Bolts19
Rocker Arm Shaft Bolts21
Vibration Damper Bolts
1972 through 197650 to 60
1977 and Later80
Water Pump Bolts10 to 15