GM HEI Ignition Module

[Ben Bruce aka First Born]

Folks, need some info.l I have two GM HEI ignition Modules.  Different numbers.  Where can I find info to determine the difference between the two.  Probably on Google, but I can't seem to ask the proper question.

 

  Numbers are:

                   908  6G22

                   908  3J21

 

  Thanks

  Ben

Edited May 28, 2019 by Ben Bruce aka First Born (see edit history)

[Brad Conley]

Any other numbers on the module?  The second set of numbers you posted above look like date codes (year, month, day).

[Ben Bruce aka First Born]

You may be right, Brad. Someone else thought the same.

  The numbers posted are stamped, I think, in white. There is a molded , raised, number, 466. on top.

  I think all modules are the same. Just curious. You have probably satisfied me.

 

  Thanks

  Ben

[Larry Schramm]

The production number would be 908.  The other number would be the date code.  The first one is probably built 1976, July 22.  The second one built 1973, September 21. 

 

908  6G22   &      908  3J21

[NTX5467]

As I recall, the GM HEI was (for sure) normal V-8 equipment on model year 1975 V-8s, with some late-'74 Chevy Z/'28s getting them.  Prior to that, it was Pontiac's pre-HEI High Energy Ignition  option (which I found out about  in a '72 Pontiac chassis service manual).  Before that, it was the Delco CD Ignition option on Chevy V-8s.

 

I'm not sure about how "universal" the GM HEI module might be.  I do know that the number of pins designates if the module is "early" or "late" (which has more pins due to the detonation limiter module in the circuit, as an external item).

 

There are two different coils, with unique wire colors, which are supposed to have different resistance values/output levels.  One was on normal engines, the other was first was on the L69 Camaro V-8s.  But from my experience, they both performed the same in my '77 Camaro 5.0L.

 

Not sure how all of this would relate to an OEM Buick application.

 

NTX5467

[Ben Bruce aka First Born]

6 hours ago, Larry Schramm said:

The production number would be 908.  The other number would be the date code.  The first one is probably built 1976, July 22.  The second one built 1973, September 21. 

 

908  6G22   &      908  3J21

 

 

  Thanks, Larry.

 

  Ben