# Engine code and date discrepancy - HELP!!



## Mcantw (Sep 7, 2008)

Reading some threads I decided to check out the numbers on my engine to ensure it is a 400cid, like I was told. Well the engine casting number is 9778789 which equates to a 65 or 66 389. The date code by this number is F278 which equates to June 27th of 1968. Front of the engine has a YF code, so if 65 or 66 a 389 and nothing equates for a 68. The F in the YF looks suspect (done with a punch??). Can't find any numbers on the front drivers side that state actual engine size and I have no reason (right now) to disassembly and pull to make sure that there is none where it shouldn't be. I know I will need this info in the future when rebuilding/replacing parts. Any help would be greatly appreciated. Mike


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## 68greengoat (Sep 15, 2005)

I'm wondering if the date code F278 is actually F276. Maybe the 6 looks like an 8. May want to double check it. As far as the engine size on the side of the block, they didn't start doing that until '68. So if you didn't find one, it probably is pre '68. Check to see too if there is V.I.N. code on the passenger front of the motor next to the timing cover. If not, it's pre late '67. If there is, the 1st digit would be a 2 for Pontiac and the 2nd digit would be the year. The last 6 would match the vehicles V.I.N if it was a numbers matching. 8 digits total. I would check the date code first. I'm thinking it's F276. The YF is probably right.


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## Too Many Projects (Nov 15, 2008)

:agree What he said. The casting code can be hard to see clearly with the engine in the car.


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## 05GTO (Oct 6, 2004)

I agree with 68greengoat regarding the date, 

The YF code shows up for both 1965 and 1966 as a 389 with 325hp, automatic transmission, 4bbl with AC. This engine was not used for the GTO and probably came from a full size b-body.


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## geeteeohguy (Feb 2, 2008)

Nothing wrong with a 389.....heck, bored over .060, it's a 400!


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## Mcantw (Sep 7, 2008)

To all, I've re-checked the numbers and nothing has changed. There is no doubt that F278 is the number. Checked the front by the timing chain and the number above the YF is 693088. Now I'm really confused since it didn't start with a 2. I do have a 4 bbl with a manual transmission without ac. I have no problem with a 389 (or whatever this ends up being) since it runs great.


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## 05GTO (Oct 6, 2004)

Mcantw said:


> To all, I've re-checked the numbers and nothing has changed. There is no doubt that F278 is the number. Checked the front by the timing chain and the number above the YF is 693088. Now I'm really confused since it didn't start with a 2. I do have a 4 bbl with a manual transmission without ac. I have no problem with a 389 (or whatever this ends up being) since it runs great.


I found a few more applications for the YF; All had a 2 bolt main.


YF Bbody 67 400 325hp Turbo 400 1x4 9786133
YF Bbody 74 400 175hp Turbo 400 1x2 481988
YF Fbody 74 400 175hp Turbo 400 1x2 481988
YF Abody 74 400 190hp Turbo 400 1x2 481988
YF Abody 73 400 230hp 3-speed 1x4 481988
YF Bbody 65 389 325hp Turbo 400 1x4 9778789
YF Bbody 66 389 325hp Turbo 400 1x4 9778789
YF Bbody 68 400 340hp Turbo 400 1x4 9790071
YF Bbody 69 400 265hp Turbo 400 1x2 9790071


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## 05GTO (Oct 6, 2004)

Mcantw said:


> The F in the YF looks suspect (done with a punch??).


Here are all of the Y letter codes;

Letter code-body-year-CID-HP-Transmission-RPO-VIN-Carb-Casting#-#bolts main

Y1 Bbody 73 400 185 Turbo 400 L-65 P 1x2 481988 2
Y2 Abody 73 350 175 Turbo 350 L-30 N 1x2 488986 2 low comp
Y2 Bbody 67 428 360 Turbo 400 1x4 9786135 4
Y3 Abody 73 400 230 Turbo 400 L-78 T 1x4 481988 2 HEI
Y3 Bbody 74 400 225 Manual L-78 T 1x4 481988 2 HEI
Y3 Bbody 74 400 225 Manual L-78 T 1x4 481988 2 HEI
Y3 Fbody 74 400 225 Manual L-78 R 1x4 481988 2 HEI
Y3 Abody 74 400 225 Manual L-78 T 1x4 481988 2
Y3 Abody 76 455 200 Turbo 400 L-75 W 1x4 500813 2
Y3 Bbody 73 400 230 Turbo 400 L-78 R 1x4 481988 2
Y3 Bbody 73 400 230 Turbo 400 L-78 T 1x4 481988 2
Y3 Bbody 76 455 200 Turbo 400 L-75 W 1x4 500813 2
Y3 Bbody 76 455 200 Turbo 400 L-75 W 1x4 500813 2
Y3 Bbody 67 428 376 Turbo 400 1x4 9786135 4
Y3 Fbody 73 400 230 Turbo 400 L-78 T 1x4 481988 2
Y4 Abody 77 400 180 Turbo 350 L-78 Z 1x4 568557 2
Y4 Bbody 73 400 185 Turbo 400 L-65 P 1x2 481988 2
Y4 Bbody 74 455 250 Turbo 400 L-75 Y 1x4 485428 2
Y4 Bbody 76 455 200 Turbo 400 L-75 U 1x4 500813 2
Y4 Bbody 77 400 180 Turbo 350 L-78 Z 1x4 568557 2
Y5 Bbody 73 350 150 Turbo 350 L-30 M 1x2 488986 2 low comp
Y6 Fbody 77 400 200 Turbo 350 L-78 Z 1x4 568557 2 Trans Am
Y6 Abody 73 400 230 4-speed L-78 T 1x4 481988 2
Y6 Abody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2
Y6 Bbody 74 455 250 Turbo 400 L-75 Y 1x4 485428 2
Y6 Bbody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2
Y6 Bbody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2
Y6 Fbody 73 400 230 4-speed L-78 T 1x4 481988 2
Y7 Abody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2 AC
Y7 Bbody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2 AC
Y7 Bbody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2 AC
Y7 Bbody 73 350 150 Turbo 350 L-30 M 1x2 488986 2 low comp
Y7 Abody 77 400 180 Turbo 350 L-78 Z 1x4 568557 2
Y8 Abody 73 455 310 Turbo 400 LS-2 X 1x4 490132 4 GTO
Y8 Bbody 73 455 310 Turbo 400 LS-2 X 1x4 490132 4 Super Duty
Y8 Fbody 73 455 310 Turbo 400 LS-2 X 1x4 490132 4 Super Duty
Y8 Fbody 74 455 290 Turbo 400 LS-2 X 1x4 490132 4 Super Duty
Y8 Abody 76 455 200 Turbo 400 L-75 W 1x4 500813 2
Y8 Bbody 76 455 200 Turbo 400 L-75 u 1x4 500813 2
Y9 Abody 74 455 250 Turbo 400 L-75 Y 1x4 485428 2 HEI
Y9 Bbody 74 455 250 Turbo 400 L-75 Y 1x4 485428 2 HEI
Y9 Bbody 74 455 250 Turbo 400 L-75 Y 1x4 485428 2 HEI
Y9 Fbody 74 455 250 Turbo 400 L-75 Y 1x4 485428 2 HEI
Y9 Fbody 77 350 170 Turbo 350 L-76 p 1x4 488986 2
Y9 Fbody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2
YA Bbody 65 389 256 Turbo 400 1x2 9778789 2 AC
YA Bbody 66 389 256 Turbo 400 1x2 9778789 2 AC
YA Abody 70 455 360 Turbo 400 L-75 1x4 9799140 4 GTO HO
YA Bbody 69 400 265 Turbo 400 1x2 9790071 2 int seat 30
YA Abody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2
YA Abody 74 350 155 Turbo 350 L-30 M 1x2 488986 2
YA Abody 75 350 155 Turbo 350 L-30 M 1x2 488986 2
YA Abody 76 350 160 Turbo 350 L-30 M 1x2 488986 2
YA Abody 77 350 170 Turbo 350 L-76 P 1x4 488986 2
YA Bbody 72 455 250 Turbo 400 L-75 Y 1x4 485428 2
YA Bbody 72 455 250 Turbo 400 L-75 Y 1x4 485428 2
YA Bbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2
YA Bbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2
YA Bbody 71 455 325 Turbo 400 L-75 1x4 485428 2
YA Bbody 71 455 325 Turbo 400 L-75 1x4 485428 2
YA Bbody 76 350 160 Turbo 350 L-30 M 1x2 488986 2
YA Bbody 77 350 170 Turbo 350 L-76 P 1x4 488986 2
YA Bbody 67 400 265 Turbo 400 1x2 9786133 2
YA Bbody 63 400 265 Turbo 400 1x2 9790071 2
YA Fbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2
YA Fbody 74 350 155 Turbo 350 L-30 M 1x2 488986 2
YA Fbody 75 350 155 Turbo 350 L-30 M 1x2 488986 2
YA Fbody 73 400 180 Turbo 350 L-78 Z 1x4 568557 2
YB Bbody 65 389 256 Turbo 400 1x2 9778789 2 AC
YB Abody 72 455 300 Turbo 400 LS-5 X 1x4 485428 4 GTO Ram Air
YB Bbody 69 400 265 Turbo 400 1x2 9790071 2 int seat 45
YB Xbody 74 350 170 Turbo 350 L-30 N 1x2 488986 2 low comp
YB Fbody 72 455 300 Turbo 400 LS-5 X 1x4 485428 4 Ram Air
YB Abody 77 350 170 Turbo 350 L-76 P 1x4 488986 2
YB Bbody 67 400 265 Turbo 400 1x2 9786133 2
YB Bbody 77 350 170 Turbo 350 L-76 P 1x4 488986 2
YB Bbody 70 400 265 Turbo 400 L-65 1x2 9799914 2
YB Bbody 70 400 265 Turbo 400 L-65 1x2 9799914 2
YB Fbody 75 350 155 Turbo 350 L-30 M 1x2 488986 2
YB Fbody 76 350 160 Turbo 350 L-30 M 1x2 488986 2
YC Abody 76 400 170 Turbo 350 L-65 N 1x2 500557 2 AC
YC Bbody 76 400 170 Turbo 350 L-65 N 1x2 500557 2 AC
YC Bbody 76 400 170 Turbo 350 L-65 N 1x2 500557 2 AC
YC Bbody 65 389 290 Turbo 400 1x2 9778789 2 AC
YC Bbody 66 389 290 Turbo 400 1x2 9778789 2 AC
YC Bbody 67 400 290 Turbo 400 1x2 9786133 2 AC
YC Abody 72 455 250 Turbo 400 L-75 Y 1x4 485428 2 GTO
YC Abody 71 455 325 Turbo 400 L-75 1x4 485428 2 GTO
YC Abody 70 455 360 4-speed L-75 1x4 9799140 4 GTO Judge HO
YC Bbody 69 400 290 Turbo 400 1x2 9790071 2 int seat 30
YC Abody 74 350 170 Turbo 350 L-30 N 1x2 488986 2 low comp
YC Fbody 74 350 170 Turbo 350 L-30 N 1x2 488986 2 low comp
YC Abody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2
YC Bbody 72 455 250 Turbo 400 L-75 Y 1x4 485428 2
YC Bbody 72 455 250 Turbo 400 L-75 Y 1x4 485428 2
YC Bbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2
YC Bbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2
YC Bbody 71 455 325 Turbo 400 L-75 1x4 485428 2
YC Bbody 71 455 325 Turbo 400 L-75 1x4 485428 2
YC Bbody 68 400 290 Turbo 400 1x2 9790071 2
YC Fbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2
YC Fbody 71 455 325 Turbo 400 L-75 1x4 485428 2
YD Bbody 67 400 290 Turbo 400 1x2 9778789 2 AC
YD Bbody 65 389 290 Turbo 400 1x2 9778789 2 AC
YD Bbody 66 389 290 Turbo 400 1x2 9778789 2 AC
YD Abody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2 High Altitude
YD Bbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2 High Altitude
YD Bbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2 High Altitude
YD Fbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2 High Altitude
YD Bbody 69 400 290 Turbo 400 1x2 9790071 2 int seat 45
YE Fbody 69 350 265 Powerglide L-30 1x2 9790079 2 AC int seat 45
YE Abody 71 455 335 Turbo 400 LS-5 1x4 483677 4 GTO Judge HO
YE Fbody 71 455 335 Turbo 400 LS-5 1x4 483677 4 HO
YE Bbody 69 400 290 Turbo 400 1x2 9790071 2 int seat 30
YE Fbody 72 455 300 Turbo 400 LS-5 X 1x4 485428 4 Ram Air
YE Bbody 65 389 325 Turbo 400 1x4 9778789 2
YE Bbody 66 389 325 Turbo 400 1x4 9778789 2
YE Bbody 67 400 325 Turbo 400 L-67 1x4 9786133 2
YE Bbody 68 400 340 Turbo 400 L-67 1x4 9790071 2
YE Bbody 70 400 290 Turbo 400 L-65 1x2 9799914 2
YF Bbody 67 400 325 Turbo 400 L-67 1x4 9786133 2 AC
YF Bbody 74 400 175 Turbo 400 L-65 R 1x2 481988 2 HEI
YF Fbody 74 400 175 Turbo 400 L-65 R 1x2 481988 2 HEI
YF Abody 74 400 190 Turbo 400 L-65 P 1x2 481988 2
YF Abody 73 400 230 3-speed L-78 T 1x4 481988 2
YF Bbody 65 389 325 Turbo 400 1x4 9778789 2
YF Bbody 66 389 325 Turbo 400 1x4 9778789 2
YF Bbody 68 400 340 Turbo 400 L-67 1x4 9790071 2
YF Bbody 69 400 265 Turbo 400 1x2 9790071 2
YG Abody 73 400 230 4-speed L-78 T 1x4 481988 2
YG Bbody 71 455 280 Turbo 400 L-75 1x4 485428 2
YG Bbody 65 389 338 4-speed 3x2 9778789 4
YG Fbody 73 400 230 4-speed L-78 T 1x4 481988 2
YH Bbody 70 455 360 Turbo 400 L-75 1x4 9799140 4 HO
YH Bbody 69 428 360 Turbo 400 1x4 9792968 2 int seat 45
YH Abody 75 400 170 Turbo 350 L-65 R 1x2 500557 2
YH Abody 77 301 135 Turbo 350 L-27 Y 1x2 525934 2
YH Abody 74 400 175 Turbo 400 L-65 R 1x2 481988 2
YH Bbody 74 400 175 Turbo 400 L-65 R 1x2 481988 2
YH Bbody 72 455 200 Turbo 400 L-75 U 1x2 485428 2
YH Bbody 75 400 170 Turbo 350 L-65 R 1x2 500557 2
YH Bbody 75 400 170 Turbo 350 L-65 R 1x2 500557 2
YH Bbody 78 400 180 Turbo 350 L-78 Z 1x4 568557 2
YH Bbody 65 421 338 Turbo 400 1x4 9778791 4
YH Bbody 66 421 338 Turbo 400 1x4 9782611 4
YH Bbody 67 428 360 Turbo 400 1x4 9786135 4
YH Bbody 68 428 375 Turbo 400 1x4 9792968 4
YH Fbody 74 400 175 Turbo 400 L-65 R 1x2 481988 2
YH Fbody 77 301 135 Turbo 350 L-27 Y 1x2 525934 2
YH Xbody 77 301 135 Turbo 350 L-27 Y 1x2 525934 2
YI Abody 67 400 360 Turbo 400 L-67 1x4 9786133 2 GTO
YJ Fbody 69 350 265 Powerglide L-30 1x2 9790079 2 AC int seat 30
YJ Abody 76 400 170 Turbo 350 L-65 N 1x2 500557 2
YJ Bbody 74 400 190 Turbo 400 L-65 P 1x2 481988 2
YJ Bbody 76 400 170 Turbo 350 L-65 N 1x2 500557 2
YJ Bbody 76 400 170 Turbo 350 L-65 N 1x2 500557 2
YJ Bbody 78 400 180 Turbo 350 L-78 Z 1x4 568557 2
YJ Bbody 65 421 356 Turbo 400 3x2 9778791 4
YJ Bbody 66 421 356 Turbo 400 3x2 9782611 4
YJ Fbody 67 326 250 Powerglide L-30 1x2 9786339 2
YJ Fbody 68 350 265 Powerglide L-30 1x2 9790079 2
YK Abody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2 High Altitude
YK Bbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2 High Altitude
YK Bbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2 High Altitude
YK Fbody 73 455 250 Turbo 400 L-75 Y 1x4 485428 2 High Altitude
YK Bbody 65 421 376 Turbo 400 3x2 9778791 4 HO
YK Bbody 68 428 390 Turbo 400 1x4 9792968 4 HO
YK Bbody 66 421 376 Turbo 400 3x2 9782611 4 HO
YK Abody 77 301 135 Turbo 350 L-27 Y 1x2 525934 2
YK Bbody 67 428 376 Turbo 400 1x4 9786135 4
YK Bbody 74 400 190 Turbo 400 L-65 P 1x2 481988 2
YK Bbody 78 400 180 Turbo 350 L-78 Z 1x4 568557 2
YK Bbody 69 428 390 Turbo 400 1x4 9792968 4
YK Fbody 77 301 135 Turbo 350 L-27 Y 1x2 525934 2
YK Xbody 77 301 135 Turbo 350 L-27 Y 1x2 525934 2
YL Abody 74 400 200 Turbo 400 L-78 S 1x4 481988 2 HEI
YL Bbody 74 400 200 Turbo 400 L-78 S 1x4 481988 2 HEI
YL Bbody 74 400 200 Turbo 400 L-78 S 1x4 481988 2 HEI
YL Fbody 74 400 200 Turbo 400 L-78 S 1x4 481988 2 HEI
YL Bbody 69 428 360 Turbo 400 1x4 9792968 2 int seat 30
YL Abody 73 350 150 Turbo 350 L-30 M 1x2 488986 2 low comp High Altitude 
YL Fbody 73 350 150 Turbo 350 L-30 M 1x2 488986 2 low comp High Altitude
YL Fbody 80 301 210 Turbo 350 LU-8 T 1x4 525934 2 Turbo
YL Abody 78 301 140 Turbo 350 L-27 Y 1x2 525934 2
YL Bbody 67 400 350 Turbo 400 L-67 1x4 9786133 2
YL Bbody 78 301 140 Turbo 350 L-27 S 1x2 525934 2
YL Bbody 66 389 333 Turbo 400 1x4 9778789 2
YM Abody 74 400 200 Turbo 400 L-78 S 1x4 481988 2 HEI
YM Bbody 74 400 200 Turbo 400 L-78 S 1x4 481988 2 HEI
YM Bbody 74 400 200 Turbo 400 L-78 S 1x4 481988 2 HEI
YM Fbody 74 400 200 Turbo 400 L-78 S 1x4 481988 2 HEI
YM Fbody 67 326 285 Turbo 400 L-76 1x4 9786339 2 HO
YM Fbody 68 350 320 Powerglide L-76 1x4 9790079 2 HO
YM Xbody 73 350 175 Turbo 350 L-30 N 1x2 488986 2 low comp High Altitude 
YM Bbody 75 400 185 Turbo 350 L-78 S 1x4 500557 2
YM Bbody 78 301 140 Turbo 350 L-27 Y 1x2 525934 2
YM Bbody 66 421 376 Turbo 400 3x2 9782611 4
YN Abody 69 350 265 Powerglide L-30 1x2 9790079 2 AC int seat 30
YN Abody 71 350 250 Powerglide L-30 1x2 481990 2
YN Abody 74 350 170 Turbo 350 L-30 N 1x2 488986 2
YN Abody 65 326 250 Powerglide L-30 1x2 9778840 2
YN Abody 66 326 250 Powerglide L-30 1x2 9778840 2
YN Abody 67 326 250 Powerglide L-30 1x2 9786339 2
YN Abody 68 350 265 Powerglide L-30 1x2 9790079 2
YN Bbody 73 400 230 Turbo 400 L-78 T 1x4 481988 2
YN Bbody 73 400 230 Turbo 400 L-78 T 1x4 481988 2
YN Bbody 71 350 250 Powerglide L-30 1x2 481990 2
YN Fbody 71 350 250 Powerglide L-30 1x2 481990 2
YN Fbody 74 350 170 Turbo 350 L-30 N 1x2 488986 2
YN Fbody 75 350 175 Manual L-76 E 1x4 488986 2
YN Fbody 80 301 140 Turbo 350 L-37 W 1x4 525934 2
YO Abody 67 326 285 Turbo 400 L-76 1x4 9786339 2 HO
YO Fbody 67 326 285 Turbo 400 L-76 1x4 9786339 2 HO
YO Bbody 73 350 150 Turbo 350 L-30 M 1x2 488986 2 low comp
YO Fbody 75 350 175 Manual L-76 E 1x4 488986 2
YP Abody 76 350 160 Turbo 350 L-30 M 1x2 488986 2 AC
YP Bbody 76 350 160 Turbo 350 L-30 M 1x2 488986 2 AC
YP Xbody 74 350 200 Turbo 350 L-76 K 1x4 488986 2 GTO low comp
YP Abody 73 400 185 Manual L-65 P 1x2 481988 2
YP Abody 71 350 250 Powerglide L-30 1x2 481990 2
YP Abody 78 301 140 Turbo 350 L-27 Y 1x2 525934 2
YP Abody 65 326 285 Powerglide L-76 1x4 9778840 2
YP Abody 66 326 285 Powerglide L-76 1x4 9778840 2
YP Abody 67 326 285 Turbo 400 L-76 1x4 9786339 2
YP Abody 68 350 320 Turbo 400 L-76 1x4 9790079 2
YP Bbody 71 350 250 Powerglide L-30 1x2 481990 2
YP Bbody 78 301 140 Turbo 350 L-27 Y 1x2 525934 2
YP Fbody 71 350 250 Powerglide L-30 1x2 481990 2
YQ Abody 67 400 360 Turbo 400 L-67 1x4 9786133 2 GTO Ram Air
YR Fbody 76 350 160 Turbo 350 L-30 M 1x2 488986 2 AC
YR Bbody 74 455 250 Turbo 400 L-75 Y 1x4 485428 2 Califorina
YR Abody 66 389 360 Powerglide 802 3x2 9778789 2 GTO
YR Abody 65 389 360 Powerglide 3x2 9778789 2 GTO
YR Abody 67 400 360 4-speed L-67 1x4 9786133 2 GTO Ram Air
YR Abody 73 350 150 Turbo 350 L-30 M 1x2 488986 2 low comp
YR Bbody 73 350 150 Turbo 350 L-30 M 1x2 488986 2 low comp
YR Fbody 73 350 150 Turbo 350 L-30 M 1x2 488986 2 low comp
YR Abody 72 350 160 Turbo 350 L-30 M 1x2 481990 2
YR Bbody 78 400 180 Turbo 350 L-78 Z 1x4 568557 2
YR Fbody 72 350 160 Turbo 350 L-30 M 1x2 481990 2
YR Fbody 72 350 175 Turbo 350 L-30 N 1x2 481990 2
YS Abody 72 400 250 Turbo 400 L-78 R 1x4 481988 2 GTO
YS Abody 71 400 300 Turbo 400 L-78 1x4 481988 2 GTO
YS Abody 65 389 335 Powerglide 1x4 9778789 2 GTO
YS Abody 66 389 335 Powerglide 1x4 9778789 2 GTO
YS Abody 68 400 350 Turbo 400 L-67 1x4 9790071 2 GTO
YS Abody 69 400 350 Turbo 400 L-67 1x4 9790071 2 GTO
YS Abody 70 400 350 Turbo 400 L-67 1x4 9799914 2 GTO
YS Xbody 74 350 200 Turbo 350 L-76 K 1x4 488986 2 GTO low comp
YS Abody 67 400 335 Turbo 400 L-67 1x4 9786133 2 GTO Califorina
YS Abody 73 400 230 Turbo 400 L-78 T 1x4 481988 2
YS Bbody 72 400 250 Turbo 400 L-78 T 1x4 481988 2
YS Bbody 72 400 250 Turbo 400 L-78 T 1x4 481988 2
YS Bbody 71 400 300 Turbo 400 L-78 1x4 481988 2
YS Bbody 71 400 300 Turbo 400 L-78 1x4 481988 2
YS Bbody 78 400 180 Turbo 350 L-78 Z 1x4 568557 2
YS Fbody 72 400 250 Turbo 400 L-78 T 1x4 481988 2
YS Fbody 73 400 230 Turbo 400 L-78 T 1x4 481988 2
YS Fbody 71 400 300 Turbo 400 L-78 1x4 481988 2
YS Fbody 75 400 185 Turbo 350 L-78 S 1x4 500557 2
YS Fbody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2
YS Fbody 70 400 330 Turbo 400 L-67 1x4 9799914 2
YT Fbody 69 400 330 Turbo 400 L-67 1x4 9790071 2 AC
YT Abody 72 400 250 Turbo 400 L-78 T 1x4 481988 2 GTO
YT Abody 73 400 230 Turbo 400 L-78 T 1x4 481988 2 High Altitude
YT Bbody 73 400 230 Turbo 400 L-78 T 1x4 481988 2 High Altitude
YT Bbody 73 400 230 Turbo 400 L-78 T 1x4 481988 2 High Altitude
YT Fbody 73 400 230 Turbo 400 L-78 T 1x4 481988 2 High Altitude
YT Abody 74 400 225 Turbo 400 L-78 T 1x4 481988 2
YT Abody 75 400 185 Turbo 350 L-78 S 1x4 500557 2
YT Abody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2
YT Bbody 74 400 225 Turbo 400 L-78 R 1x4 481988 2
YT Bbody 72 400 250 Turbo 400 L-78 T 1x4 481988 2
YT Bbody 72 400 250 Turbo 400 L-78 T 1x4 481988 2
YT Bbody 74 400 225 Turbo 400 L-78 T 1x4 481988 2
YT Bbody 75 400 185 Turbo 350 L-78 S 1x4 500557 2
YT Bbody 75 400 185 Turbo 400 L-78 S 1x4 500557 2
YT Bbody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2
YT Bbody 76 400 185 Turbo 350 L-78 Z 1x4 500557 2
YT Bbody 78 400 180 Turbo 350 L-78 Z 1x4 568557 2
YT Bbody 66 421 338 4-speed 1x4 9782611 4
YT Fbody 72 400 250 Turbo 400 L-78 T 1x4 481988 2
YT Fbody 74 400 225 Turbo 400 L-78 T 1x4 481988 2
YT Fbody 75 400 185 Turbo 350 L-78 S 1x4 500557 2
YT Fbody 67 400 325 Turbo 400 L-67 1x4 9786133 2
YT Fbody 68 400 330 Turbo 400 L-67 1x4 9790071 2
YU Bbody 66 389 290 Turbo 400 1x2 9778789 2 AC
YU Abody 69 350 265 Powerglide L-30 1x2 9790079 2 AC int seat 45
YU Abody 72 350 160 Turbo 350 L-30 M 1x2 481990 2 Califorina
YU Bbody 72 350 160 Turbo 350 L-30 M 1x2 481990 2 Califorina
YU Bbody 75 455 200 Turbo 400 L-75 W 1x4 500813 2 Califorina
YU Fbody 72 350 160 Turbo 350 L-30 M 1x2 481990 2 Califorina
YU Fbody 72 350 175 Turbo 350 L-30 N 1x2 481990 2 Califorina
YU Fbody 69 350 265 Powerglide L-30 1x2 9790079 2 int seat 45
YU Abody 77 400 180 Turbo 350 L-78 Z 1x4 568557 2
YU Abody 70 350 255 Powerglide L-30 1x2 9799916 2


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## 05GTO (Oct 6, 2004)

Mcantw said:


> Checked the front by the timing chain and the number above the YF is 693088. Now I'm really confused since it didn't start with a 2.


Here is the vin code 68greengoat is talking about;










VIN number location on late 1967 to 1979 engines. It starts with “2”, 
a letter for the assembly plant, then the vehicle serial number.​
Also, 65, 66 and the first part of 67 the casting number was located on the distributor pad, mid year of 67 the casting number was moved behind the #8 cylinder as seen in this picture. 








Pictures from; Fred’s Pontiac Information


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## Mcantw (Sep 7, 2008)

The casting number and date code are on the distributor pad. Had to remove the securing bracket to completely read the casting number. Both numbers are in good condition and clean so easy to read. The vin (?) and engine code I gave was not in the exact location as the picture. It is higher up on the block but still near the timing cover on the passenger side. I can see no other numbers in this area without removing interference.


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## Too Many Projects (Nov 15, 2008)

The number you posted is the engine application code. The VIN is way down next to the timing cover just above the oil pan and stamped in a vertical orientation. The numbers are smaller and hard to see. Try using a small mirror to look.


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## 68greengoat (Sep 15, 2005)

Out of curiosity, check the date code on the heads. They were often swapped to different year blocks but not always. They could be the heads that came with that block. The code is located on the outside of the head right below the lip of the valve cover. The codes are located in the same place for each head. You will have to crouch down to see the code since it's tucked right under the valve cover lip and you may need to use a light . You do not need to remove the valve cover to see the code. What number does the code end in?


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## Mcantw (Sep 7, 2008)

Just did a bunch a surfing and I think I have everything (I hope ) figured out. Casting number - good. Date code must be a 6 no matter how hard I look and it still seems like an 8. For the front. I guess some engines have three numbers stamped. Top number is an engine production number (explains starting with a 6) and under is the YF code. The engine VIN code is unreadable due to placement by water pump/timing cover. I would have to remove to read. Mystery is over and I have a 389.


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## Mcantw (Sep 7, 2008)

68GreenGoat, I don't see any head date codes. I'm looking right under the valve covers on both sides on the outer sides. It's getting dark out here but I was using the flashlight. I'm guessing you mean the dates are located right under the valve cover lip?


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## 68greengoat (Sep 15, 2005)

Mcantw said:


> Just did a bunch a surfing and I think I have everything (I hope ) figured out. Casting number - good. Date code must be a 6 no matter how hard I look and it still seems like an 8. For the front. I guess some engines have three numbers stamped. Top number is an engine production number (explains starting with a 6) and under is the YF code. The engine VIN code is unreadable due to placement by water pump/timing cover. I would have to remove to read. Mystery is over and I have a 389.


Not to put a fly in the ointment, but, if you know for sure that there is a V.I.N. code in the exact spot that is shown in a pic that 05GTO submitted(he used an arrow to show location) means it's a post late '67 block. If there is no number there, then it's a pre-late '67 block('65, '66 and early '67). The block casting number you submitted is used only for '65/'66 389's.

The head code is towards the front of the side of the head on a "flat" which the code points up for viewing. About 1/2" below valve cover lip. Maybe 05GTO can submit a pic for that too.... That's where it is located on my '68, maybe it's different for '65/'66.


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## 05GTO (Oct 6, 2004)

68greengoat said:


> The head code is towards the front of the side of the head on a "flat" which the code points up for viewing. About 1/2" below valve cover lip. Maybe 05GTO can submit a pic for that too.... That's where it is located on my '68, maybe it's different for '65/'66.


This is a post 73 head, they started stamping an extra code on the heads in 73 to indicate the chamber size. But the casting and date code are pretty much in the same area but closer to the front for the earlier date codes.
This picture is from wallace racing.


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## Mcantw (Sep 7, 2008)

My location is not the same as where 05GTO but as shown below for 65 and later. Hope the link works since I couldn't get a picture to post here.


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