Engine Codes

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1964 Engine Codes & Production Totals
1965 Engine Codes & Production Totals
1966 Engine Codes & Production Totals
1967 Engine Codes & Production Totals
1968 Engine Codes & Production Totals
1969 Engine Codes & Production Totals
1970 Engine Codes & Production Totals
1971 Engine Codes & Production Totals
1972 Engine Codes & Production Totals
1973 Engine Codes (Early Production)
1973 Engine Codes (Late Production) & Production Totals
1974 Engine Codes & Production Totals

1964 Engine Codes & Production Totals

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Engine C.I.D	Carb. Type	Trans. Type	Std. Code	Compression Ratio	Horsepower
389	3X2	3-SPD	76X	10.75:1	348
389	3X2	4-SPD	76W	10.75:1	348
389	3X2	4-SPD¹	76XW	10.75:1	348
389	3X2	4-SPD²	769	10.75:1	348
389	3X2	AUTO.	77J	10.75:1	348
389	4BBL	3-SPD	78X	10.75:1	325
389	4BBL	4-SPD¹	78W	10.75:1	325
389	4BBL	4-SPD¹	78XW³	10.75:1	325
389	4BBL	4-SPD²	789	10.75:1	325
389	4BBL	AUTO.	79J	10.75:1	325

Special Notes:
¹4spd.M-20 Wide Ratio
²4spd.M-21 Close Ratio
³To use left over 3-spd. blocks the factory stamped a letter (W) after the (X) to mark them as 4-spd. blocks.

1964 Production Totals

Convertible	6,644
Coupe	7,384
Hardtop	18,422

Total Production	32,450

389 3x2 Engine	8,245
389 4-BBL Engine	24,205

1965 Engine Codes & Production Totals

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Engine C.I.D	Carb. Type	Trans. Type	Std. Code	Compression Ratio	Horsepower
389	3X2	MAN.	WS	10.75:1	360
389	3X2	AUTO.	YR	10.75:1	360
389	4BBL	MAN.	WT	10.75:1	335
389	4BBL	AUTO.	YS	10.75:1	335

Special Notes:
Although never shown in production figures, there were over the counter, and possibly dealer installed ram air packages sold for the 1965 GTO.

A 421 cubic inch motor could be ordered and dealer installed in a 65 GTO, but there were no factory built 421 GTO`s. A fully documented 421 GTO is very desirable and extremely rare. If not documented this application is incorrect. 1965 Production Totals

Convertible	11,311
Coupe	8,319
Hardtop	55,722
Total Production	75,352
389 3X2	20,547
389 4BBL	54,805
Manual	56,378
Automatic	18,974

1966 Engine Codes & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Type	Std. Code	Calif. Code	Compression Ratio	Horsepower
389	4BBL	MAN	WT	WW	10.75:1	335
389	4BBL	AUTO	YS	XE	10.75:1	335
389	3X2	MAN	WS	WV	10.75:1	360
389	3X2	AUTO	YR	YR	10.75:1	360
389	3X2	MAN(RA)¹	XS	XS	10.75:1	360

Special Notes:
¹ Although never shown in production figures there were approximately 25 to 35 factory built 1966 ram air GTO`s (XS package). It is estimated that 300 dealer ram air packages were sold for 66 GTO`s.

A 421 cubic inch motor could be ordered and dealer installed in a 66 GTO, but there were no factory built 421 GTO`s. A fully documented 421 GTO is very desirable and extremely rare. If not documented this application is incorrect. 1966 Production Totals

Convertible	12,798
Coupe	10,363
Hardtop	73,785
Total Production	96,946
389 3X2	19,045
389 4BBL	77,901
Manual	61,279
Automatic	35,667

1967 Engine Codes & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Calif. Code	Compression Ratio	Horsepower
400	4-BBL	3-SPD. MAN	WT	WW	10.75:1	335
400 H.O.	4-BBL	3-SPD.MAN	WS	WV	10.75:1	360
400	4-BBL	4-SPD. MAN	WT	WV	10.75:1	335
400 H.O.	4-BBL	4-SPD. MAN	WS	WV	10.75:1	360
400 R.A.	4-BBL	4-SPD. MAN	XS	YR	10.75:1	360
400	4-BBL	AUTO.	YS	YS	10.75:1	335
400	2-BBL	AUTO.	XM	XL	8.60:1	255
400 H.O.	4-BBL	AUTO.	YZ	YZ	10.75:1	360
400 R.A.	4-BBL	AUTO.	XP	XP	10.75:1	360

Special Note:
A 428 cubic inch motor could be ordered and dealer installed in a 67 GTO, but there were no factory built 428 GTO`s. A fully documented 428 GTO is very desirable and extremely rare. If not documented this application is incorrect. 1967 Production Totals

Convertible	9,517
Coupe	7,029
Hardtop	65,176
Total Production	81,722
400 Ram Air	751
400 H.O.	13,827
400 2BBL.	2,967
400 Std. Engine	64,177
Manual	39,128
Automatic	42,594
400 Ram Air (Auto)	138
400 Ram Air (Manual)	613

1968 Engine Codes & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Compression Ratio	Horsepower
400	4-BBL	3-SPD.MAN	WT	10.75:1	350
400 H.O.	4-BBL	3-SPD.MAN	WS	10.75:1	360
400	4-BBL	4-SPD.	WT	10.75:1	350
400 H.O.	4-BBL	4-SPD.	WS	10.75:1	360
400 R.A.	4-BBL	4-SPD.MAN	XS	10.75:1	360
400	4-BBL	AUTO.	YS	10.75:1	350
400	2-BBL	AUTO.	XM	8.60:1	265
400 H.O.	4-BBL	AUTO.	YZ	10.75:1	360
400 R.A.	4-BBL	AUTO.	XP	10.75:1	360

Special Note:
A 428 cubic inch motor could be ordered and dealer installed in a 68 GTO, but there were no factory built 428 GTO`s. A fully documented 428 GTO is very desirable and extremely rare. If not documented this application is incorrect. 1968 Production Totals

Hardtop	400 Ram Air (Manual)	757
	400 Ram Air (Auto)	183
	400 H.O. (Manual)	6,197
	400 H.O. (Auto)	3,140
	400 2BBL. (Manual)	0
	400 2BBL. (Auto)	2,841
	400 Std.Engine (Manual)	25,371
	400 Std.Engine (Auto)	39,215
Total Hardtop		77,704
Convertible	400 Ram Air (Manual)	92
	400 Ram Air (Auto)	22
	400 H.O. (Manual)	766
	400 H.O. (Auto)	461
	400 2BBL. (Manual)	0
	400 2BBL. (Auto)	432
	400 Std.Engine (Manual)	3,116
	400 Std.Engine (Auto)	5,091
Total Convertible		9,980
Total Production		87,684

1969 Engine Codes & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Compression Ratio	Horsepower
400	4-BBL	3SPD.MAN	WT	10.75:1	350
400 R.A.III	4-BBL	3SPD.MAN	WS	10.75:1	366
400	4-BBL	4SPD.MAN	WT	10.75:1	350
400 R.A.III	4-BBL	4SPD.MAN	WS	10.75:1	366
400 R.A.IV	4-BBL	4SPD.MAN	WW	10.75:1	370
400	4-BBL	AUTO.	YS	10.75:1	350
400	2-BBL	AUTO.	XX	8.60:1	265
400 R.A.III	4-BBL	AUTO.	YZ	10.75:1	366
400 R.A.IV	4-BBL	AUTO.	XP	10.75:1	370

1969 Production Totals

Hardtop	400 Ram Air IV (Manual)	549
	400 Ram Air IV (Auto)	151
	400 Ram Air III (Manual)	6,143
	400 Ram Air III (Auto)	1,986
	400 2BBL. (Manual)	0
	400 2BBL. (Auto)	1,246
	400 Std. Engine (Manual)	22,032
	400 Std. Engine (Auto)	32,744
Hardtop		58,126
Hardtop Judge		6,725
Total Hardtop		64,851

Convertible	400 Ram Air IV (Manual)	45
	400 Ram Air IV (Auto)	14
	400 Ram Air III (Manual)	249
	400 Ram Air III (Auto)	113
	400 2BBL. (Manual)	0
	400 2BBL. (Auto)	215
	400 Std. Engine (Manual)	2,415
	400 Std. Engine (Auto)	4,385
Convertible		7,328
Convertible Judge		108
Total Convertible		7,436
Total Judge		6,833
Total Production		72,287

1970 Engine Codes & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Compression Ratio	Horsepower
400	4-BBL	3SPD.MAN	WT	10.25:1	350
400 R.A.III	4-BBL	3SPD.MAN	WS	10.50:1	366
455	4-BBL	3SPD.MAN	WA	10.00:1	360
400	4-BBL	4SPD.MAN	WT	10.25:1	350
400 R.A.III	4-BBL	4SPD.MAN	WS	10.50:1	366
400 R.A.IV	4-BBL	4SPD.MAN	WW	10.50:1	370
455	4-BBL	4SPD.MAN	WA	10.00:1	360
400	4-BBL	AUTO.	YS	10.25:1	350
400 R.A.III	4-BBL	AUTO.	YZ	10.50:1	366
400 R.A.IV	4-BBL	AUTO.	XP	10.50:1	370
455	4-BBL	AUTO.	YA	10.00:1	360

1970 Production Totals

Hardtop	400 Ram Air IV (Manual)	627
	400 Ram Air IV (Auto)	140
	400 Ram Air III (Manual)	3,054
	400 Ram Air III (Auto)	1,302
	455 4BBL. (Manual)	1,761
	455 4BBL. (Auto)	1,986
	400 Std.Engine (Manual)	9,348
	400 Std.Engine (Auto)	18,148
Hardtop		32,737
Hardtop Judge		3,629
Total Hardtop		36,366
Convertible	400 Ram Air IV (Manual)	24
	400 Ram Air IV (Auto)	13
	400 Ram Air III (Manual)	174
	400 Ram Air III (Auto)	114
	455 4BBL. (Manual)	158
	455 4BBL. (Auto)	241
	400 Std.Engine (Manual)	887
	400 Std.Engine (Auto)	2,173
Convertible		3,615
Convertible Judge		168
Total Convertible		3,783

Total Judge		3,797
Total Production		40,149

1971 Engine Codes & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Compression Ratio	Horsepower
400	4-BBL	3SPD.MAN	WT	8.20:1	300
455 H.O.	4-BBL	3SPD.MAN	WL	8.40:1	335
400	4-BBL	4SPD.MAN	WK	8.20:1	300
455 H.O.	4-BBL	4SPD.MAN	WC	8.40:1	335
400	4-BBL	AUTO.	YS	8.20:1	300
455	4-BBL	AUTO.	YC	8.20:1	325
455 H.O.	4-BBL	AUTO.	YE	8.40:1	335

1971 Production Totals

Hardtop	455 H.O. (Manual)	476
	455 H.O. (Auto)	412
	455 4BBL. (Manual)	0
	455 4BBL. (Auto)	534
	400 Std. Engine (Manual)	2,011
	400 Std. Engine (Auto)	6,421
Hardtop		9,497
Hardtop Judge		357
Total Hardtop		9,854
Convertible	455 H.O. (Manual)	21
	455 H.O. (Auto)	27
	455 4BBL. (Manual)	0
	455 4BBL. (Auto)	43
	400 Std. Engine (Manual)	79
	400 Std. Engine (Auto)	508
Convertible		661
Convertible Judge		17
Total Convertible		678

Total Judge		374
Total Production		10,532

1972 Engine Codes & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Compression Ratio	Horsepower
400	4-BBL	3SPD.MAN	WS	8.20:1	250
400	4-BBL	4SPD.MAN	WK¹	8.20:1	250
455 H.O.	4-BBL	4SPD.MAN	WM²	8.40:1	300
400	4-BBL	AUTO.	YT	8.20:1	250
455	4-BBL	AUTO.	YK	8.20:1	250
455 H.O.	4-BBL	AUTO.	YB	8.40:1	300
400	2-BBL	AUTO.	XX	8.60:1	265

Special Notes:
¹ Indicates Wide Ratio 4-Spd.
² Indicates Close Ratio 4-Spd.
1972 Production Totals

Coupe	455 H.O. (Manual)	3
	455 H.O. (Auto)	7
	455 4BBL. (Manual)	0
	455 4BBL. (Auto)	5
	400 Std. Engine (Manual)	59
	400 Std. Engine (Auto)	60
Total Coupe		134
Hardtop	455 H.O. (Manual)	310
	455 H.O. (Auto)	325
	455 4BBL. (Manual)	0
	455 4BBL. (Auto)	235
	400 Std. Engine (Manual)	1,519
	400 Std. Engine (Auto)	3,284
Total Hardtop		5,673

Total Production		5,807

1973 Engine Codes (Early Production)

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Calif. Code	Compression Ratio	Horsepower
400	4-BBL	3SPD.MAN	WS	--	8.0:1	230
400	4-BBL	4SPD.MAN	WK¹	--	8.0:1	230
400	4-BBL	4SPD.MAN	WP	--	8.0:1	230
400	4-BBL	AUTO.	YS	--	8.0:1	230
400	4-BBL	AUTO.	--	ZS	8.0:1	230
400	4-BBL	AUTO.	YY¹	--	8.0:1	230
400	4-BBL	AUTO.	Y3¹	--	8.0:1	230
400	4-BBL	AUTO.	YT²	--	8.0:1	230
455	4-BBL	AUTO.	YC	--	8.0:1	250
455	4-BBL	AUTO.	--	ZC	8.0:1	250
455	4-BBL	AUTO.	YA¹	--	8.0:1	250
455	4-BBL	AUTO.	--	ZA	8.0:1	250
455	4-BBL	AUTO.	YK²	--	8.0:1	250
455	4-BBL	AUTO.	YD³	--	8.0:1	250

1973 Engine Code (Late Production) & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Calif. Code	Compression Ratio	Horsepower
400	4-BBL	3SPD.MAN	YF	--	8.0:1	230
400	4-BBL	4SPD.MAN	Y6	--	8.0:1	230
400	4-BBL	4SPD.MAN	YG¹	--	8.0:1	230
400	4-BBL	AUTO.	XN	--	8.0:1	230
400	4-BBL	AUTO.	XX¹	--	8.0:1	230
400	4-BBL	AUTO.	XK²	--	8.0:1	230
455	4-BBL	AUTO.	XE	--	8.0:1	250
455	4-BBL	AUTO.	XL¹	--	8.0:1	250
455	4-BBL	AUTO.	X7²	--	8.0:1	250
455	4-BBL	AUTO.	XM³	--	8.0:1	250

Special Notes:
¹ Cars Equipped With Unitized Ignition
² High Country Use
³ High Country Use Equipped With Unitized Ignition
1973 Production Totals

Coupe	455 4BBL. (Manual)	0
Coupe	455 4BBL. (Auto)	25
Coupe	400 4BBL. (Manual)	187
Coupe	400 4BBL. (Auto)	282
Total Coupe		494
Sport Coupe	455 4BBL. (Manual)	0
Sport Coupe	455 4BBL. (Auto)	519
Sport Coupe	400 4BBL. (Manual)	926
Sport Coupe	400 4BBL. (Auto)	2,867
Total Sport Coupe		4,312

Total Production		4,806

1974 Engine Codes & Production Totals

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Engine C.I.D.	Carb. Type	Trans. Code	Std. Code	Calif. Code	Compression Ratio	Horsepower
350	4-BBL	MAN.	WP	--	7.62:1	200
350	4-BBL	AUTO.	YP	--	7.62:1	200
350	4-BBL	AUTO.¹	--	ZP	7.62:1	200
350	4-BBL	AUTO.	YS	--	7.62:1	200

Special Notes:
All 1974 GTO's were equipped with a 350 cubic inch V8, rated at 200 Horsepower at 4400 rpm. All had a 7.62:1 compression ratio. All were 4BBL equipped cars.

¹ This denotes California usage only. Manual transmissions were not available for use in California in 1974. The 1974 GTO's that were sold in California were equipped with M38 transmissions (hydra-matic) and a 3:08:1 rear axle. 1974 Production Totals

Hatchback	350 4BBL. (Manual)	687
	350 4BBL. (Auto)	1,036
Total Hatchback		1,723
Coupe	350 4BBL. (Manual)	2,487
	350 4BBL. (Auto)	2,848
Total Coupe		5,335

Total Production		7,058

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Updated August 7, 1996

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