FR Engine Blocks

The Boss block is a 4.6L deck height, 94mm cylinder bore cast iron block. The block uses a proprietary iron mix to yield the strongest possible casting strength with the least porosity and greatest consistency. NOTE: The Boss 5.0L modular block does not have a finish milled head deck surface and the cylinder bores are rough honed. WARNING: This part is designed and intended for competition use only. It should not be installed on a vehicle that is driven on public roads and highways. Installation of this art on a vehicle driven on public roads and highways is likely to violate U. S. And Canadian laws and regulations relating to motor vehicle emissions. 5.0L Cast Iron Modular Boss Engine Block Modular Boss Engine Block.