Originally Posted by stallion0606
how to keep that engine cool that those engines are known for
When you hear these things, sometimes you want to find out what the truth is. From what I've researched on this topic, some braintrust built a 400 with 350 heads. They were not drilled as the 400's had been and the subsequent steam pockets that were formed at low rpm's caused either detonation from a hot spot or the head raised enough that the motor spit the head gasket out.
The GM engineers supposedly found that the 400 would wash out the steam pockets at the corner of the siamezed cylinders if the motor were run at higher rpm's. Problem is, these cars were sold to granny also and granny will not tolerate spittin' a head gasket out on the way to Bingo. So, the holes in the heads match up with holes in the decks allowing the motor to pass cooling water through the holes and relieve the hotspots at lower rpm's to fix the problem.
Now, of course, the genius who failed to drill the steam holes in the heads before assembly crabbed to anyone who would listen to him, that a 400 will overheat as the nature of the beast. This is some kind of WOW news to some fellows and they repeat it as gospel.
Drill the heads yourself with a drill press and some fixtures.