Edelbrock Performer RPM (7577) and 360 Magnum CI heads

Rear coolant lines help keep the cylinder head more evenly cool across the whole head. This is worth some power. No sense in having one side of the head hot possibly detonating!
MoPar suggests taking it out of the center in some of there writings.

If you only added rear lines, it’s a plus. If you did rear and center, that’s as good as it gets for removing coolant out of the head.