The 153 4 cyl chevy engine uses the same compresion distance as the chevy 302 Z28 engine.The Z28 is a 4 inch bore and the 4 cyl is 3.875.That means you will have to bore to 4 inches.It is only a .125 over bore and the 4 cyl can take it.You will also have to remove the dome on the Z28 pistons.Bob