It’s used by racers, it’s similar to concrete, often called “hard block.” A “street fill” is usually considered up to the bottom of the core plug holes. You may need extra oil cooling to make up for it. If you’re just drag racing most don’t bother. You can see elevated oil temps on the street, likely won’t notice if you don’t monitor before and after.Not familiar with block filler, I will need to research that. Did this affect the cooling?
Money & Effort well spent !Those certainium rods work well.. just pricey, repairing a good part —priceless!