Install the crankshaft main bearing caps by installing the #1 timing cover.
Measure the diameter with a micrometer (X1) crankshaft bearings. The diameter value must be between 55.997-56.017 mm (for M4R engine) and 51.997-52.017 mm (for H4J engine).
Compare the resulting diameter value with the diameter class marked on the cylinder block (see table «Crankshaft bearing diameter class»).