It can be done. Solid and filled to the freeze plugs won't be the same and you'll be surprised at how little coolant capacity the engine will have. Anti-freeze is a no-no in a drag car and water will quickly turn to steam in the heads. How much are you willing to spend on monitoring the temps that may or may not get out of control? What methods could be used in short order to cool things down in late rounds? It's not uncommon to have a 7 rd. bracket race. 5 rounds is only 32 cars. I would think extra oil capacity and a way to cool/circulate it between rds. might work. Run the alcohol on the super fat side. FWIW, half the nitro pumped through fuel cars is coolant! A Top Fuel engine will weld itself together WFO after about 10 secs.