70 ls6 correct radiator ???

[graperat]

What is the correct radiator for a 70 ls6 chevelle with an auto trans and 3.31 gear ratio?? what letters should be stamped on the tanks?? where is the radiator date coded also?? thanks

[Mr70]

Dennis
It should normally be an 3 core with that combination.
Do you have a Buildsheet with callout?
When the LS6 Came with either an M-22,or a TH400 trans.& a 4:10 Rearend it automatically got a 4 core Radiator.
The 4:10 was the distinguishing component for them.
1970 LS6 Radiator Codes:
3 Core
BQ-Man. Trans
BR-Auto Trans.

4 Core
PA-Man Trans
PD-Auto Trans
These suffix codes were stamped onto a tag on the Passengers side tank.It was a seperate tag from the Radiator tank.

[graperat]

Thanks for the quick reply and helpfull info.The build sheet is not on hand.Car was a basketcase 15 years ago when i bought it.If the tag is not on the tank,will the tanks themselves have any letters on them?? Since my car was a 3.31 i guess i can go with the 3 core since it would be easier to find,anybody have that puppy?? thanks

[graperat]

what other car would have this same correct radiator,i just bought a 70 ss 454 monte carlo for parts and it is an auto 3 core rad,i didnt even think about a ls6 being nothing but a 4 core.i assume they all are harrison radiators??

[Mr70]

I deleted my sentence in earlier post,a 4 core wasn't possible with a 3:31/LS6.Sorry for the mis-information.
The Harrison Tanks are correct,and the Monte Carlo tanks will work,as long as they are an Auto car as yours is.
You might want to get the Rad re-cored though.
Suffix on 3 core rad tanks should be:
I A-on Drivers tank.
X I-on Passengers tank.

I have a 3 core Rad here now.You will also need the Correct 3 core radiator shroud for it.
This shroud is unique in that it is different from the 4 core shroud,and is not correctly repoped today.
I have one of those too.

[graperat]

my other 70 ls6 that has the 3.31 man trans has a 4 core with all the correct stamps and tank tag(got info from the ls6 benchmark website)The dealer sheet showing the options and price markup on the car shows a heavy duty raditor up grade for a pretty cheap price. I guess that explains that 4 core story on that car.I only have a copy of this sheet obviously for the dealers eyes only,the guy i got the car from gave me the copy that he recieved 22 years ago from the guy he bought it from.Someone somewhere has some important paperwork that i need,that is why in another post i sure would like to know how to crack that oregon DMV. I do know the original dealership,do they keep that type of info if there still in business??