Engine Tune-Up Specs 1970-72

* All timing figures are before Top Dead Center.
* Values in parenthesis are for California engines.
* Where two idle values are separated by a slash, the second is with idle speed solenoid disconnected.


ENGINE                                     DIST      TIMING-DEG   INTAKE  FUEL          IDLE RPM       TARGET
TYPE               HP /        PLUG       POINTS       W/TRANS    VALVE   PUMP-PSI       W/TRANS        COMP
CYL-DISP    CARB   TORQUE   TYPE   GAP   DWELL  GAP   MAN  AUTO   OPENS   PRESSURE     MAN     AUTO     RATIO
__________  ____  _______   __________   __________   _________   _____   ________   ________________  _______
(1970)
6-250 Chevy  1v   155/240   R46T  .035   31-34 .019   TDC   4B    16deg     4-5      830-750  630-600    8.5:1
8-350        2v   250/355   R46S  .030   28-32 .016   10B  10B    16deg   5.5-6.5      750      575        9:1
8-350        4v   310/390   R45S  .030   28-32 .016   10B  10B    16deg   5.5-6.5      650      575    10.25:1
8-350 (W31)  4v   325/360   R43S  .030   28-32 .014   14B  14B    40deg   5.5-6.5      750      625     10.5:1
8-455        2v   320/500   R45S  .030   28-32 .016   ---   8B    20deg   5.5-6.5      ---      575    10.25:1
8-455 Cutlas 4v   365/500   R44S  .030   28-32 .016   --- 12.5    20deg   5.5-6.5      ---      600     10.5:1
8-455 Vista  4v   365/500   R45S  .030   28-32 .016   ---   8B    24deg   5.5-6.5      ---      575     10.5:1
8-455 442    4v   365/500   R44S  .030   28-32 .016   12B  12B    24deg   5.5-6.5      700      650     10.5:1
8-455 (W30)  4v   370/500   R44S  .030   28-32 .016    8B   8B    56deg   5.5-6.5      700      650     10.5:1
(1971)
6-250 Chevy  1v   145/230   R46TS .035   31-34 .019    4B   4B    16deg     4-5        600      575        8:1
8-350        2v   240/350   R46S  .040   28-32 .016   10B  10B    14deg   5.5-6.5      750      600      8.5:1
8-350        4v   260/360   R45S  .040   28-32 .016   10B  12B    14deg   5.5-6.5      750      600      8.5:1
8-455        2v   280/445   R46S  .040   28-32 .016   ---   8B    20deg   5.5-6.5      ---      600      8.5:1
8-455        4v   320/460   R46S  .040   28-32 .016   ---   8B    20deg   5.5-6.5      ---      600      8.5:1
8-455        4v   340/460   R45S  .040   28-32 .016   10B  10B    24deg   5.5-6.5      750      600      8.5:1
8-455 (W30)  4v   350/460   R45S  .040   28-32  .06   12B  10B    56deg   5.5-6.5      765      600      8.5:1
(1972)
8-350        2v   160/275   R46S  .040   28-32 .016    8B 8B(6B)  16(22)  5.5-6.5      750    650/550    8.5:1
8-350 Duals  2v   175/295   R46S  .040   28-32 .016    8B 8B(6B)  16(22)  5.5-6.5      750    650/550    8.5:1
8-350        4v   180/275   R46S  .040   28-32 .016    8B  12B    16(22)  5.5-6.5      750      600      8.5:1
8-350 Duals  4v   180/275   R46S  .040   28-32 .016    8B  12B    16(22)  5.5-6.5      750      600      8.5:1
8-455        4v   225/360   R46S  .040   28-32 .016   10B   8B    30deg   5.5-6.5      750      600      8.5:1
8-455 Duals  4v   250/370   R46S  .040   28-32 .016   10B   8B    30deg   5.5-6.5      750      600      8.5:1
8-455        4v   270/370   R46S  .040   28-32 .016   10B   8B    30deg   5.5-6.5      750      600      8.5:1
8-455 (W30)  4v   300/410   R45S  .040   28-32 .016   12B  10B    56deg   5.5-6.5      750      650      8.5:1