can I use my 318 radiator after 400 big block is swapped in?

[tahoemuk]

I'm slowly getting my parts together- I have a high horsepower 400 thats going in and I didnt get a radiator yet- do I have to buy a new radiator and if so which one so I need? Does it have the internal oil cooler or do I get an external?

[Chryco Psycho]

generally a 318 rad will nto cool a big block but it might if you had a 26 " wide rad on the 318
get a 3 core rad to fit your car with an internal trans cooler