Mopar 340 crank to 360 block Main Bearing Spacers. These bearing spacers can be used to de-stroke an engine in order to fit into a certain class of racing. They allow for better choices of connecting rod lengths and piston designs. The spacers fit into a 360 engine block allowing 318/340 bearings, rear main seal, & cranks to be installed. Requires line honing for final sizing. Call us if you would like a set.