Chevrolet Big Block Tune-Up and Torque Specifications

Chevrolet V8 Firing Order

Chevrolet Big Block Tune-Up Specifications

Engine	Year	Horsepower	Note	AC Spark	Spark Plug	Point	Dwell	Firing	Ignition	Hot Idle	Hot Idle	Valve Lash	Valve Lash
				Pug No.	Gap	Gap	Angle	Order	Timing BTDC	Std. Trans	Auto Trans	Intake	Exhaust
348	59-60		With Hydraulic Lifters	44N	0.035	0.016	30	18436572	8°
348	59-60		With Solid Lifters	44N	0.035	0.016	30	18436572	12°			.008H	.018H
348	61		With Hydraulic Lifters	44N	0.035	0.019	30	18436572	8°			1 Turn	1 Turn
348	61		With Solid Lifters	43N	0.035	0.019	30	18436572	12°			.008H	.018H
409	61	360	With Solid Lifters	43N	0.035	0.019	30	18436572	12°			.008H	.018H
409	62	380 or 409hp	With Solid Lifters	43N	0.035	0.019	29	18436572	12°			.008H	.018H
409	63	340	With Hydraulic Lifters	43N	0.035	0.019	28-32	18436572	10°			1 Turn	1 Turn
409	63-64	400 or 425hp	With Solid Lifters	43N	0.035	0.019	28-32	18436572	12°			.008H	.018H
409	64	340	With Hydraulic Lifters	43N	0.035	0.019	28-32	18436572	6°			1 Turn	1 Turn
396	65	325hp	Without Transistor Ignition	43N	0.035	0.016	28-32	18436572	4°	500, AC on	475 In Drive, AC on
396	65	325hp	With Transistor Ignition	43N	0.035	0.016	28-32	18436572	6°	500, AC on	475 In Drive, AC on
396	65	425hp		43N	0.035	0.016	28-32	18436572	10°	800, AC on	–
409	65	340hp	With Hydraulic Lifters	C42N	0.035	0.016	28-32	18436572	8°	475, AC on	450 In Drive, AC on	Hydraulic	Hydraulic
409	65	400hp	With Solid Lifters	C42N	0.035	0.016	28-32	18436572	12°	975, AC on	–	.018H	.030H
396	66	325hp	With Hydraulic Lifters	43N	0.035	0.016	28-32	18436572	4°	500, AC on	500 In Drive, AC on	1 Turn	1 Turn
396	66	325hp 4	With Hydraulic Lifters	43N	0.035	0.016	28-32	18436572	4°	500, AC on	500 In Drive, AC on	1 Turn	1 Turn
427	66	390hp	Without Air Injection reactor emission system	43N	0.035	–	–	18436572	4°	550, AC on	550 In Drive, AC on
427	66	390hp	With Air Injection reactor emission system	43N	0.035	–	–	18436572	4°	550, AC on	550 In Drive, AC on
427	66	425hp	With Solid Cam	43N	0.035	–	–	18436572	10°	800, AC on	–	.020H	.024H
396	67	325hp	Without Air Injection reactor emission system	43N	0.035	0.019	28-32	18436572	4°	500, AC on	500 In Drive, AC on	1 Turn	1 Turn
396	67	325hp	With Air Injection reactor emission system	43N	0.035	0.019	28-32	18436572	4°	700, AC on	500 In Drive, AC on	1 Turn	1 Turn
396	67	350hp	With Hydraulic Lifters	43N	0.035	0.019	28-32	18436572	4°	700, AC on	500 In Drive, AC on	1 Turn	1 Turn
396	67	375hp	With Solid Cam	R43N	0.035	0.019	28-32	18436572	10°	800, AC on	–	.020H	.024H
427	67	385hp	With Hydraulic Lifters	43N	0.035	0.019	28-32	18436572	4°	550, AC on	550 In Drive, AC on	1 Turn	1 Turn
427	67	385hp	With Air Injection reactor emission system	43N	0.035	0.019	28-32	18436572	4°	700, AC on	550 In Drive, AC on	1 Turn	1 Turn
396	68	325hp	With Hydraulic Lifters	43N	0.035	0.019	28-32	18436572	4°	700, AC Off	600 In Drive, AC Off	1 Turn	1 Turn
396	68	375hp	With Solid Lifters	43N	0.035	0.019	28-32	18436572	4°	750, AC Off	–	.024H	.028H
427	68	385hp	With Hydraulic Lifters	43N	0.035	0.019	28-32	18436572	4°	700, AC Off	600 In Drive, AC Off	1 Turn	1 Turn
427	68	430hp	With Solid Lifters	R43XL	0.035	–	–	18436572	12°	1000	–	.022H	.024H
427	68	425 or 435hp	With Solid Lifters	R43N	0.035	0.019	28-32	18436572	4°	750	750	.024H	.028H
396	69	265hp	With Standard Transmission	R44N	0.035	0.019	28-32	18436572	TDC	700, AC Off	–	1 Turn	1 Turn
396	69	265hp	With Automatic Transmission	R44N	0.035	0.019	28-32	18436572	4°	–	600 In Drive, AC Off	1 Turn	1 Turn
427	69	425hp	With Solid Lifters	R43N	0.035	0.019	28-32	18436572	4°	750, AC Off	750 In Drive, AC Off	.024H	.028H
427	69	335hp	With Hydraulic Lifters	R44N	0.035	0.019	28-32	18436572	4°	800, AC Off	600 In Drive, AC Off	1 Turn	1 Turn
427	69	390hp	With Hydraulic Lifters	R43N	0.035	0.019	28-32	18436572	4°	800, AC on	600 In Drive, AC on	1 Turn	1 Turn
427	69	425hp	With Hydraulic Lifters	R43N	0.035	0.019	28-32	18436572	4°	750, AC Off	750 In Drive, AC Off	1 Turn	1 Turn
427	69	430hp	With Solid Lifters	R43XL	0.035	–	–	18436572	12°	1000		.022H	.024H
427	69	435hp	With Solid Lifters	R43N	0.035	–	–	18436572	4°	750 AC Off	750 In Deive	.024H	.028H
400	70	265hp	With Automatic Transmission	R44	0.035	0.019	28-32	18436572	8°	–	600 In Drive	1 Turn	1 Turn
454	70	345hp	With Hydraulic Lifters	R44T	0.035	0.019	28-32	18436572	6°	–	600 In Drive	1 Turn	1 Turn
454	70	360hp	With Hydraulic Lifters	R43T	0.035	0.019	28-32	18436572	6°	700	600 In Drive	1 Turn	1 Turn
454	70	390hp	With Hydraulic Lifters	R43T	0.035	0.019	28-32	18436572	6°	700	600 In Drive	1 Turn	1 Turn
454	70	450hp	With Solid Lifters	R43XL	0.035	–	–	18436572	8°	700	600	.024H	.028H
400	71	255hp	With Standard Transmission	R44TS	0.035	0.019	31-34	18436572	4°	550	–	1 Turn	1 Turn
400	71	255hp	With Automatic Transmission	R44TS	0.035	0.019	31-34	18436572	8°	–	550 In Drive	1 Turn	1 Turn
400	71	300hp	With Hydraulic Lifters	R44TS	0.035	0.019	31-34	18436572	8°	–	600 In Drive	1 Turn	1 Turn
454	71	365hp	With Hydraulic Lifters	R43TS	0.035	0.019	31-34	18436572	8°	–	600 In Drive	1 Turn	1 Turn
454	71	425hp	With Standard Transmission	R44TS	0.035	–	–	18436572	8°	700		.024H	.028H
454	71	425hp	With Automatic Transmission	R44TS	0.035	–	–	18436572	12°		600	.024H	.028H
402	72		With Hydraulic Lifters	R44T	0.035	0.016	29-31	18436572	8°	–	600 In Drive	1 Turn	1 Turn
400	72		With Hydraulic Lifters	R44T	0.035	0.016	29-31	18436572	6°	–	600 In Drive	1 Turn	1 Turn
454	72		With Hydraulic Lifters	R44T	0.035	0.016	29-31	18436572	8°	–	600 In Drive	1 Turn	1 Turn
400	73-74			R44T	0.035	0.016	29-31	18436572	8°	–	600 In Drive	1 Turn	1 Turn
454	73-74			R44T	0.035	0.016	29-31	18436572	10°	–	600 In Drive	1 Turn	1 Turn
400	75			R44TX	0.06	–	–	18436572	8°	–	600 In Drive	1 Turn	1 Turn
454	75			R44TX	0.06	–	–	18436572	16°	–	600 In Drive	1 Turn	1 Turn

Chevrolet Big Block Torque Specifications

Engine	Year	Note	Spark Plug	Heads	Intake Manifold	Exhaust Manifold	Rocker Arm Stud	Rocker Arm Cover	Connecting Rod	Main Bearing	Flywheel to crank’	Dampner front Puly
			Ft. Lbs	Ft. Lbs	Ft. Lbs	Ft. Lbs	Ft. Lbs	Inch Lbs	Ft. Lbs	Ft. Lbs	Ft. Lbs	Ft. Lbs
396	66-67	2 bolt Main	25	80	30	20	50	50 inch	50	95	60	85
396	66-67	4 bolt Main	25	80	30	20	50	50 inch	50	104	60	85
396	68-69	2 bolt Main	25	80	30	20	50	50 inch	45	95	60	85
396	68-69	4 bolt Main	25	80	30	20	50	50 inch	45	104	60	85
396/402	70		15	80	30	20	50	50 inch	50	105	65	85
402	71-72		15	80	30	20	50	50 inch	50	105	65	85
427	66	2 bolt Main	25	80	30	20	50	50 inch	50	95	60	85
427	66	4 bolt Main	25	80	30	20	50	50 inch	50	104	60	85
427	67-69	2 bolt Main With Cast Iron Heads	25	80	30	20	50	50 inch	50	95	60	85
427	67-69	4 bolt Main With Cast Iron Heads	25	80	30	20	50	50 inch	50	104	60	85
427	67-69	2 bolt Main Aluminium Heads Short Bolt	25	65	30	20	50	50 inch	50	95	60	85
427	67-69	4 bolt Main Aluminium Heads Short Bolt	25	65	30	20	50	50 inch	50	104	60	85
427	67-69	2 bolt Main Aluminium Heads Long Bolt	25	75	30	20	50	50 inch	50	95	60	85
427	67-69	4 bolt Main Aluminium Heads Long Bolt	25	75	30	20	50	50 inch	50	104	60	85
454	1970-75		15	80	30	20	50	50 inch	50	105	65	85