Max HP debate
I'd recommend a short fill of hard bloc for a race engine, even tho you already said no to that. Cooling would not be a problem for the short duration of run time at a dragstrip. A street engine is rarely run at full power and also would not have a cooling problem, assuming you have an efficient cooling system.
Now if you are going road racing or stock car racing, or top speed racing, then cooling would be a challenge due to the much longer duration under full power. In that case, you would want to go to an aftermarket block with full length water jackets.
Drag racing is actually quite easy on engines due to the short run time. This engine will probably be used in a 6.0 ET 1/8 mile car which means it only has to turn 750 revolutions at full power. In the 1/4 mile it would turn 1,125 revolutions under full power in a 9 sec pass. Whereas a circle track racer would be turning tens of thousands of revolutions under full power in a single race and a stock block would be much more likely to fail due to simple metal fatigue.
This hypothetical question is fun to consider and allows everyone to explore the various issues associated with engine longevity. But in reality this question can be simply answered with the old phrase "don't be penny smart and pound foolish."