Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent
Straight Edge 303-D039 (D83L-4201-A) or equivalent
Use a straight edge and a feeler gauge to inspect the cylinder block for flatness. If the cylinder block is distorted, install a new short block assembly.
Fig 1: Checking Cylinder Block For Flatness Using Straight Edge & Feeler Gauge