Harrison Copper Radiator tag MC4

[Mike E.]

Any idea what this comes off of? Not a 68-72, that much I know, but looking for info on origin. Similar in appearance and size to original 68-72 radiator tags (copper radiators) but different code.
radiator tag (1).jpg

[Joe L.]

Re: Harrison Copper Radiator tag MC4

Any idea what this comes off of? Not a 68-72, that much I know, but looking for info on origin. Similar in appearance and size to original 68-72 radiator tags (copper radiators) but different code.
[ATTACH=CONFIG]100740[/ATTACH]

Mike-------


GM #3030199 radiator used for all 1973-75 Corvettes as well as some 1976 Corvettes.

[Mike E.]

Re: Harrison Copper Radiator tag MC4

Thanks,Joe. Might you have a master list of those? And a follow-up question; the clips that hold the overflow hose, and which are located just below the ID tag, have a 2-letter code on those. Any list of those codes anywhere? Thanks in advance.

[Robert R.]

Re: Harrison Copper Radiator tag MC4

Mike-------


GM #3030199 radiator used for all 1973-75 Corvettes as well as some 1976 Corvettes.

According to the 3rd Edition of the 73-74 TIM&JG the MC broadcast code is used on 74 Corvettes with M40 & C60 options. My original big block 74 with AC and auto trans has that same tag "MC4." The JG states that it is not known what the single digit represents. Maybe it represents the year of manufacture or production.

[Mike E.]

Re: Harrison Copper Radiator tag MC4

According to the 3rd Edition of the 73-74 TIM&JG the MC broadcast code is used on 74 Corvettes with M40 & C60 options. My original big block 74 with AC and auto trans has that same tag "MC4." The JG states that it is not known what the single digit represents. Maybe it represents the year of manufacture or production.

Thanks. 70 to 72 codes all end in 9, so who knows? Hopefully someone does!

[Joe L.]

Re: Harrison Copper Radiator tag MC4

Thanks,Joe. Might you have a master list of those? And a follow-up question; the clips that hold the overflow hose, and which are located just below the ID tag, have a 2-letter code on those. Any list of those codes anywhere? Thanks in advance.

Mike-----


Yes, I have master lists but they're only for 1976-82 model years. I don't know of any such tables that existed for prior model years although some of the same radiators were used for prior model years and the codes would be the same. In addition, the tables are for ALL radiators used in ALL GM vehicles those years. So, the vast majority of those shown are not applicable to Corvettes. Lastly, the tables only relate radiator part number to broadcast code. They provide no information as to what applications the radiator or broadcast code apply to. So, additional cross-referencing has to be performed to determine application for any particular broadcast code. Even then, it may not be definitive inasmuch as any particular radiator part number (and broadcast code) might be applicable to multiple applications, including non-Chevrolet GM applications.

I do not currently have any information on the codes on the clips.

[Tom R.]

Re: Harrison Copper Radiator tag MC4

Working the 75-77 3rd edition revision, the following table is a draft and 75 applications the least confirmed. What we are finding, as one would expect, is the applications were being consolidated and limited to standard and heavy-duty. Transmission selection all called out the same radiator with ports for cooler lines for M40s. When we revised for the 73/74, we were not able to reconcile the number next to the code.

radiator table.jpg

[Mike E.]

Re: Harrison Copper Radiator tag MC4

Tom,
With the MI and MK tags,have you found a third character (number) on them? If so, what have you found?
Thanks!

Working the 75-77 3rd edition revision, the following table is a draft and 75 applications the least confirmed. What we are finding, as one would expect, is the applications were being consolidated and limited to standard and heavy-duty. Transmission selection all called out the same radiator with ports for cooler lines for M40s. When we revised for the 73/74, we were not able to reconcile the number next to the code.

[ATTACH=CONFIG]100758[/ATTACH]

[Tom R.]

Re: Harrison Copper Radiator tag MC4

Tom,
With the MI and MK tags,have you found a third character (number) on them? If so, what have you found?
Thanks!

Well this gets interesting. I'm posting an MK tag from a 78 L48 C60 car that shows a number and GM# at the top...the 5558 application. You'll see why the table above is draft where it shows MK as heavy-duty (but a different #). IN 78 ML became heavy-duty with L82, C60s. Remember 78 has the bigger window and requiring more cooling capacity but not necessarily in the context of the engine compartment.

But the car is a November 10, 1977 built car...so the 7? Month? July? I just haven't figured this out and we are not getting a lot of good data from 75-77 car owners to close the gap.

radiator Tag_MK_78.jpg