Strokers run warmer???

I noticed my new 408 ran a little hotter than the old 360, but the old 360 was loose as a goose so it didn't make much frictional heat. I have a 2 core 26" radiator (universal Summit aluminum) and hv pump in mine and it keeps the 408 cool. Have even taken it out on a 90 degree day and it didn't go over 200