1999 Volvo Penta "WT" Models Workshop Manual, Page 62Get this manual
Piston Selection
Check the used piston to cylinder bore clearance
Measure:
1Cylinder bore diameterUse telescoping bore gauge, located 2.56 in(55 mm) below the top of the cylinder bore
2Piston diameterMeasure the piston skirt at right angle to the piston pin, at the centerline of the piston pinORCS507