Ignition Timing

Set timing at idle speed with distributor vacuum line disconnected and opening taped closed.

Synchro-mesh

6° BTDC

With A.I.R. (Except 326" 285 HP)

⁽¹⁾ 4° ATDC

(326" 285 HP)

⁽¹⁾ 6° BTDC

Auto. Trans. (All)

6° BTDC

⁽¹⁾	A.I.R. system is used with Synchro-mesh transmissions ONLY on Tempest models. Initial timing is "ATDC" on some engines.

Fig 1: V8 Ignition Timing Marks

Courtesy of GENERAL MOTORS COMPANY