Just did and engine swap in my 69. It's now got a 755hp 582. I bought a 4 row champion radiator with dual fans off ebay fans are supposed to be 1250 cfm each. At cruising speed the car will maintain around 190 for a while then slowly starts to climb the longer you run it at idle the temp goes up steadily at 55mph the car will hold 210 for a while then start to rise after about 10 minutes now that I drilled a hole in the thermostat Do I need different fans? Radiator? What do y'all think?

 

Can you hear the fans kicking on? Also, do you have them set up as pushers or pullers. Could always try a lower temp stat.

 

Their pullers and yes their turning on

 

As suggested in other forums, try an OE style 7-blade fan with clutch and OE shroud.

 

Lol thanks but There's no way I'm gonna fit an OE fan and shroud in this thing

 

could you show a picture as to why not

 

Are your fans mounted directly onto the radiator, or on a flat aluminum shroud that mounts to the radiator? If you have the shroud, you might want to try going without it. I know 2 guys who had similar heating issues like you did, and after suggesting they remove the shroud (mount the fans directly on the radiator), the heat problem was cured. The flat shroud surrounding the fans acts like a blocker, stifling air movement. Now, if that shroud was tapered out to each fan, then you'd have more of a funnel effect where the fans can pull air through the entire dimension of the radiator. Of course, if your fans are already directly, that blows that idea.

 

I'm going to guess that your running the correct mixture of water and antifreeze? What about one of the water wetters that are designed make your setup more efficient? Also are you sure you worked out all the air in the system?

 

I am having the same issues with a Champion radiator as well with my blown 420 sbc in my vette. Starting to think it might be the radiator

 

The 4 row cores don't cool as well as two 1" rows do. And I agree with Chuck's theory of removing the shroud. I had one on my radiator with a BBC, and before installing it the car ran a little too warm. After putting the shroud on, it overheated so bad that I had to do a roadside removal of the shroud, so I could get home!