OEM Ignition/Door keys

[eric8]

Being one to obsess over genuine OEM details when it comes to my 77 C10, my next quest is to find the proper NOS ignition and door key. All I have are the Ace Hardware versions.
Based on my research, I need an E and H coded key for the ignition and door (GM# 1154606 & 1154607, respectively). Looking at GM parts catalogs, it seems GM changed these key codes every 4 years? For instance, E and H blanks are for 69, 73, 77, and 81 model years.
This of course piqued my curiosity. Even though every GM key blank looks the same, I assume there are subtle differences that won’t let a 1976 key blank be cut to fit a 1977 ignition?
Can anyone shed light how this works? Yes it’s mainly me nerding out for my own curiosity.

[ron350]

The long groves and ridges are different from one lettered key to another lettered key.
Like your E key can't be inserted in6to a H keyway.

[eric8]

That makes sense and seemed to be the conclusion I had reached. Only thing that confused me is that when I had a spare ignition key made it seemed like they were “oh you have the classic square head GM key” and just quickly grabbed the GM shape blank off the rack. I don’t recall them looking at key codes etc but maybe they were doing more behind the scenes than I saw.

[LockDoc]

Originally Posted by eric8

Being one to obsess over genuine OEM details when it comes to my 77 C10, my next quest is to find the proper NOS ignition and door key. All I have are the Ace Hardware versions.
Based on my research, I need an E and H coded key for the ignition and door (GM# 1154606 & 1154607, respectively). Looking at GM parts catalogs, it seems GM changed these key codes every 4 years? For instance, E and H blanks are for 69, 73, 77, and 81 model years.
This of course piqued my curiosity. Even though every GM key blank looks the same, I assume there are subtle differences that won’t let a 1976 key blank be cut to fit a 1977 ignition?
Can anyone shed light how this works? Yes it’s mainly me nerding out for my own curiosity.

Before 1973 the pickups came from the factory with one key profile that worked the doors and ignition. That changed in '73 when GM started using the two key system. The key profiles changed every year up to about 1983 but repeated every few years.

Here is what I came up with. One thing you have to remember is that over the years part numbers change.

The key blanks will only fit the locks they were designed for. (Except).... Gm supplied Universal door and ignition locks for almost all vehicles. Universal locks would accept any key profile and were less secure. The reason they did this was so that the dealers and locksmiths wouldn't have to carry all of the different locks. They could have one door lock or ignition lock on hand that would fit many different vehicles..... Also remember that the lock cylinders themselves were interchangeable between years ('73-'78 & '79-'87) so you may find any key profile lock cylinder in any truck.

I didn't have a lot of time to put this together so if anyone sees any glaring errors please let me know.

1973 Ignition:
Key: Groove 56, "E" Keyway
Original GM Key Blank # 7025014
Cross Reference to other brands of blanks: 320404
---------------------------------------------------------------------------------

1973 Doors:
Key: Groove 57, "H" Keyway
Original GM Key Blank # 7025019
Cross Reference to other brands of blanks: 320405
---------------------------------------------------------------------------------

1974 Ignition:
Key: Groove 58, "J" Keyway
Original GM Key Blank # 7025282
Cross Reference to other brands of blanks: 320470
------------------------------------------------------------------------------

1974 Doors:
Key: Groove 58, "K" Keyway
Original GM Key Blank # 7025288
Cross Reference to other brands of blanks: 320471
----------------------------------------------------------------------

1975 Ignition:
Key: Groove 50, "A" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320588
----------------------------------------------------------------------

1975 Doors:
Key: Groove 51, "B" Keyway
Original GM Key Blank # 7027281
Cross Reference to other brands of blanks: 320589
---------------------------------------------------------------------

1976 Ignition:
Key: Groove 54, "C" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320652
---------------------------------------------------------------------

1976 Doors:
Key: Groove 55, "D" Keyway
Original GM Key Blank #
Cross Reference to other brands of blanks: 320653
--------------------------------------------------------------------

1977 Ignition:
Key: Groove 56, "E" Keyway
Original GM Key Blank # 7025014
Cross Reference to other brands of blanks: 320404
--------------------------------------------------------------------

1977 Doors:
Key: Groove 57, "H" Keyway
Original GM Key Blank # 7025019
Cross Reference to other brands of blanks: 320405
-------------------------------------------------------------------

1978 Ignition:
Key: Groove 58, "J" Keyway
Original GM Key Blank # 7025282
Cross Reference to other brands of blanks: 320470
-----------------------------------------------------------------=

1978 Doors:
Key: Groove 58, "K" Keyway
Original GM Key Blank # 7025288
Cross Reference to other brands of blanks: 320471
--------------------------------------------------------------------

1979 Ignition:
Key: Groove 50, "A" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320588
------------------------------------------------------------------

1979 Doors:
Key: Groove 51, "B" Keyway
Original GM Key Blank # 7027281
Cross Reference to other brands of blanks: 320589
------------------------------------------------------------------

1980 Ignition:
Key: Groove 54, "C" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320652
------------------------------------------------------------------

1980 Doors:
Key: Groove 55, "D" Keyway
Original GM Key Blank #
Cross Reference to other brands of blanks: 320653
------------------------------------------------------------------

1981 Ignition:
Key: Groove 56, "E" Keyway
Original GM Key Blank # 7025014
Cross Reference to other brands of blanks: 320404
------------------------------------------------------------------

1981 Doors:
Key: Groove 57, "H" Keyway
Original GM Key Blank # 7025019
Cross Reference to other brands of blanks: 320405
-----------------------------------------------------------------

1982 Ignition:
Key: Groove 58, "J" Keyway
Original GM Key Blank # 7025282
Cross Reference to other brands of blanks: 320470
-----------------------------------------------------------------

1982 Doors:
Key: Groove 58, "K" Keyway
Original GM Key Blank # 7025288
Cross Reference to other brands of blanks: 320471
-----------------------------------------------------------------

1983 Ignition:
Key: Groove 50, "A" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320588
-----------------------------------------------------------------

1983 Doors:
Key: Groove 51, "B" Keyway
Original GM Key Blank # 7027281
Cross Reference to other brands of blanks: 320589
-----------------------------------------------------------------

1984 Ignition:
Key: Groove 50, "A" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320588
-----------------------------------------------------------------

1984 Doors:
Key: Groove 51, "B" Keyway
Original GM Key Blank # 7027281
Cross Reference to other brands of blanks: 320589
-----------------------------------------------------------------

1985 Ignition:
Key: Groove 50, "A" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320588
-----------------------------------------------------------------

1985 Doors:
Key: Groove 51, "B" Keyway
Original GM Key Blank # 7027281
Cross Reference to other brands of blanks: 320589

1986 Ignition:
Key: Groove 50, "A" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320588
-----------------------------------------------------------------

1986 Doors:
Key: Groove 51, "B" Keyway
Original GM Key Blank # 7027281
Cross Reference to other brands of blanks: 320589
----------------------------------------------------------------


1987 Ignition:
Key: Groove 54, "C" Keyway
Original GM Key Blank # 7027275
Cross Reference to other brands of blanks: 320652
------------------------------------------------------------------

1987 Doors:
Key: Groove 55, "D" Keyway
Original GM Key Blank #
Cross Reference to other brands of blanks: 320653

[Dead Parrot]

Originally Posted by eric8

That makes sense and seemed to be the conclusion I had reached. Only thing that confused me is that when I had a spare ignition key made it seemed like they were “oh you have the classic square head GM key” and just quickly grabbed the GM shape blank off the rack. I don’t recall them looking at key codes etc but maybe they were doing more behind the scenes than I saw.

Years ago for college money, I worked in a discount store that made keys. After a while, you knew which 2 or 3 key blanks to check and then match the ends. No lookup needed.


Thanks LockDoc for the info. Saved for future reference. My 75 is one that has a swapped ignition. Now has a E key. Doors are still the B key.

[eric8]

Originally Posted by LockDoc

Before 1973 the pickups came from the factory with one key profile that worked the doors and ignition. That changed in '73 when GM started using the two key system. The key profiles changed every year up to about 1983 but repeated every few years.

Here is what I came up with. One thing you have to remember is that over the years part numbers change.

The key blanks will only fit the locks they were designed for. (Except).... Gm supplied Universal door and ignition locks for almost all vehicles. Universal locks would accept any key profile and were less secure. The reason they did this was so that the dealers and locksmiths wouldn't have to carry all of the different locks. They could have one door lock or ignition lock on hand that would fit many different vehicles..... Also remember that the lock cylinders themselves were interchangeable between years ('73-'78 & '79-'87) so you may find any key profile lock cylinder in any truck.

I didn't have a lot of time to put this together so if anyone sees any glaring errors please let me know.

Thank you for compiling this info. My current keys are Ilco branded and have part numbers B44 and B45, which cross over to the correct E and H lock codes for my model year, so looks like I have all original locks.
More nerd info:
The original GM parts book lists a 'B&S number' of 320404 and 320405 for an E and H key code set. The B&S number apparently stands for Briggs and Stratton. I'm assuming of the small engine builder variety?

[LockDoc]

Originally Posted by Dead Parrot

Years ago for college money, I worked in a discount store that made keys. After a while, you knew which 2 or 3 key blanks to check and then match the ends. No lookup needed.


Thanks LockDoc for the info. Saved for future reference. My 75 is one that has a swapped ignition. Now has a E key. Doors are still the B key.

No problem. I posted the info for the '67-'72 trucks a few years ago.

https://67-72chevytrucks.com/vboard/...d.php?t=246485

Originally Posted by eric8

Thank you for compiling this info. My current keys are Ilco branded and have part numbers B44 and B45, which cross over to the correct E and H lock codes for my model year, so looks like I have all original locks.
More nerd info:
The original GM parts book lists a 'B&S number' of 320404 and 320405 for an E and H key code set. The B&S number apparently stands for Briggs and Stratton. I'm assuming of the small engine builder variety?

Yes, Briggs & Stratton supplied the locks and keys for GM (and many others) since about 1920, They were bought out by Strattec who still supplies locks and keys for the auto industry.
.