Heavy duty radiator
 

It's time to replace my radiator, which is listed as a heavy duty radiator on the glove box. The original radiator was replaced at some point with a non-stock replacement that just doesn't fit right. Here's what I've got: 1970 C-10, 307, manual transmission, no A/C. I don't know if the original was a 3 or 4 core, so any help is appreciated!

Re: Heavy duty radiator
 

I've had 2 core or 4 core original style radiators in the old trucks I've had, never a 3. But I'm no expert. I bought a 4 core original brass and copper radiator like the stock one when I replaced the heavy duty radiator in my shortbed with AC. I paid a little over $200 shipped. If you already have the thicker radiator, you won't need to buy different hold downs. They do make replacement aluminum radiators that are often 3 core or 2 wide cores. I personally don't like the way they look or fit, but that's just me.

Re: Heavy duty radiator
 

HD rad were usually 4 core and put in A/C trucks. The non A/C trucks with the 3 Spd tranny had mostly 3 cores. What doesn't fit right? If it's the lower rubber mounts that are too wide to seat the rad in then, I would suspect you need a 4 core.

Re: Heavy duty radiator
 

Another indication maybe what engine was installed also. If it originaly came with a 6, 307, or big block. 2 core, 3 core likewise.

Re: Heavy duty radiator
 

Thanks for the help Sammy and rsavage. Sammy - I haven't done a thorough inspection to see what doesn't fit right yet. The truck had the original radiator when I got it about 15 years ago, but my brother took it to a shop a few years later to have a new engine installed (it was originally a 307 and he replaced it with another 307). When the shop installed the engine, they told him it needed a new radiator too, so they put something in that they made "fit", but wasn't a stock replacement. It doesn't look like the original radiator, and it sits too high. It's leaking now, so I am going to go with a stock replacement.