We suggest that you chose what block works for your intended build.Consider the power level,combo parts,time constraints,availability as well as a realistic budget.Research reliable sources of experiences and results from respected builder and ask questions as to why the preferr a specific block and the advantages as well as the disavantages.If your building under a 1200 HP engine most after market blocks would work fine,If your got for higher HP,goe for the best block your budget can afford.