1970-1971 GS Radiators Revisited…

Discussion in 'The Big Chill' started by dynaflow, Aug 2, 2019.

  1. dynaflow

    dynaflow shiftless...

    This project started innocently enough with verifying my cooling system. Nope, replacement radiator, no tag or embossed tanks. No problem, just needs some research. What I found here and on radiator assembly chart was inconsistent, and nothing at all on internet about our radiators.

    I learned a lot and rather than let info just fade away, I’m making a combined ’70-’71 GS radiator chart with radiator tag and hd cooling info. Might be useful and hopefully clear up confusion.

    Almost done, but need help with 3 radiator tags, SB, SE, and SF. I need tank and core codes for SB and SE, and core code for SF. Then I can post chart…
  2. copperheadgs1

    copperheadgs1 copperheadgs1

    Confusion is the word for those charts. I don’t think the assembly line workers always got it right either. It’s a pity someone couldn’t reproduce them. Brass radiator production and repair is a lost art. Interested to see the fruits of your labor.
  3. dynaflow

    dynaflow shiftless...

    ...and assembly line substitution stories. SJ (and SS in '71) could substitute for all but HD. Never understood SF, just use plugged SE. I'm sure cost engineers had reasons...

    In case anyone needs pic of what I'm looking for;
  4. copperheadgs1

    copperheadgs1 copperheadgs1

    Wasn’t there an SW or is my mind failing too?
  5. dynaflow

    dynaflow shiftless...

    ...yes there was. That was the HD I7 option in '70, or Extra HD I3 in '71, or included in Stage 1 option both years...
  6. copperheadgs1

    copperheadgs1 copperheadgs1

    Pretty sure My GSX had SW. I managed to find one. It sure kept the engine cool. Had it done with Maine Cores.
    Brett Slater likes this.
  7. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    My Production Order Body Final for my GS says SW. Duane says that is GS Stage1, Any Trans, with A/C.
  8. dynaflow

    dynaflow shiftless...

    ...just another thing to drive you nuts...according to '70 assy manual radiator chart, A/C equipped GSXs got an SW, non A/C got an SJ. Chart says "all models" can get SW by ordering option I7 HD cooling...but, GSX order form doesn't have I7, sooo...o_O Does anyone have evidence of a '70 GSX with I7 option?

    ...for '70 and '71, Stage1 got an SW. In '70, a non-Stage GSX with A/C got an SW, everything else non-Stage with A/C (and GSX without) got an SJ unless I7 - HD Cooling option ordered. In '71 Buick cleaned up the HD Cooling vs Ex HD Cooling confusion by removing "HD Cooling" from option A1 - Stage 1 description, changing option I7 - HD Cooling from "Ex HD radiator" (SW) to "HD radiator" (SJ), and adding option I3- Ex HD Radiator. What got Buick into trouble in first place was trying to explain options/exceptions with words. If I got it right, my expanded chart should be clearer...

    Found tank codes for SB in of all places "Parts For Sale," plus verified SB has 2-row core, and yes Duane, I write this stuff down.:) Still want core codes for SB and SF, and everything for SE. With these 5 bits of info, chart will be done...
  9. BuickV8Mike

    BuickV8Mike SD Buick Fan

    Would all this info apply to 1969? My question with all this is....How can you tell a 70 from 71 tank or 68 from 69 without any dates codes on them? I love this thread. Radiators are a real mystery.
  10. Duane

    Duane Member

    You can tell which year the radiator is if you have the tag. The number on the bottom right corner is the last digit of the year.

    I don"t remember offhand if it is the model year or the year of manufacture but if you look at the above example it is an 8, which would stand for 1968.
  11. Duane

    Duane Member

    SB Radiator tag codes

    CF SB

    I have some other radiator codes but right now I can not find the sheets. If I do I will post them.
  12. dynaflow

    dynaflow shiftless...

    ...Duane comes thru again. Updated sample radiator tag pic to show year code...

    ...thank you, chart also updated. If anyone else has SE or SF tag info, please...

    ...year code on sample radiator tag changed my SS understanding. '71 assy manual page 11-4.2 list of revisions shows SS radiator added 10-26-70, I "assumed" that meant SS introduced on that date. Clearly sample tag's year code refutes that. New assumption; SS existed since '68 model year for other division(s), Buick started using it 10-26-70, and since it was for same GS applications as SJ, that would imply that when assembly plant supply of SJs ran out post 10-26-70, GSs would get SSs. This also explains why my '72 version of Master Parts Book has no SJ (or SW) part#s, only SS part# as SJ/SW field replacement back thru '69...
  13. dynaflow

    dynaflow shiftless...

    ...best guess is there's a date code on tank. As for tag, we'd need multiple examples of same radiator code with different year codes to disprove code is "model year code," until then I'm sticking with model year code...:)
  14. copperheadgs1

    copperheadgs1 copperheadgs1

    there is a single letter for month on a tank. No year that I have seen.
    BuickV8Mike likes this.
  15. Duane

    Duane Member

    John states, '71 assy manual page 11-4.2 list of revisions shows SS radiator added 10-26-70, I "assumed" that meant SS introduced on that date. Clearly sample tag's year code refutes that.

    John, that means that Buick introduced the radiator on that date....................however I believe Oldsmobiles had been using the radiators previously.......and Buick may have used them earlier as well. You would have to look at the other year assembly manuals to figure that out.

    You have to understand that Harrison made the radiators for ALL the GM divisions, not just Buick.

    PS. There is a date code on the passenger side tank. It is a "Month" date code. The dating systems used depended on how important the part was. If it was real important then they checked the part by the day and often the shift it was built on. They must have felt the radiators were only so important, because they had the year on the tag and the month on the tank, so they could only tell which month the radiator was built.
    BuickV8Mike likes this.
  16. dynaflow

    dynaflow shiftless...

    I’m not a radiator expert; chart is pure research. If you find errors, let me know. Core codes for “SE” and “SF” radiators are blank because I can’t find them. If you know them, help me finalize chart.

    Because ’70 GSX radiator choice is different from GSs, it’s separate.

    Code “SS” radiator supersedes “SJ.” Start date is engineering date; actual implementation came later. Cars built after date could have had “SJ” or “SS.” To complicate identifying late “SJ” as original, if radiator replaced in service with OEM, it would have been with an “SS.” In ‘72 edition of Buick Master Parts Book, Radiator Group 1.219, every entry that originally would have had an “SJ” radiator has an “SS” part number. Also true for “SW,” a possible topic for another thread…o_O

    “HD COOLING” is an optional radiator upgrade. A/C-equipped GSs got an “SJ” or “SS,” except “STG1” or “70 GSX” which got an “SW.” In ’70, “SJ” A/C GSs could get an “SW” with “I7” option. In ’71, non-A/C GSs could get an “SJ” or “SS” with “I7,” and A/C GSs could get the “SW” with “I3.” Buick finally “defines” “SJ” as HD and “SW” as EX-HD.

    If you have your “build sheet,” original radiator code is in box 45 of GMAD New Car Manifest, or box labelled “RADIATOR” on Production Order Body – Final.

    10/20/19 edit: I learned today that my idea to combine years into a single chart is flawed. Changes don't carry between years. Without supporting documentation, the only accurate way (thanks to Duane) to determine "original" radiator is to use your year's Assembly Manual "Radiator" page, paying attention to "Revision Record" radiator addition dates, to find correct radiator based on your build date. Details such as tag/tank/core info are still valid.

    Last edited: Oct 20, 2019
  17. tdacton

    tdacton Gold Level Contributor

    This is great information! What I feel would add for my learning is.....
    1. Picture of a left tank describing a general area where the tank code is located.
    2. Picture of a right tank describing a general area where the tank code is located.
    3. Picture(s) of a radiator describing a general area where the tag is located.
    Thanks again for this effort and everyone's contributions!
  18. Brett Slater

    Brett Slater Super Moderator Staff Member

    Passenger's side tank of mine - before I painted it.

    "D" is for April.


    This is the tag that would be found more toward the bottom of the same side tank as above.

  19. thepartsman

    thepartsman Back Ordered Again ?

    Hope this helps.....

    For those following at home in your '70 BTN it's page 65 1970 RADIATOR.jpg
    Brett Slater likes this.
  20. thepartsman

    thepartsman Back Ordered Again ?

    Again for those at home in the '71 BTN it's page 58 & 59 1971 RADIATOR1.jpg 1971RADIATOR2.jpg
    tdacton likes this.

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