Fitting Pistons

Measure piston diameter at 90-degree angle to piston in, on piston pin center line. Measure cylinder bore diameter 2 1/2" below cylinder block deck. Determine piston clearance. If piston clearance is not within specification, replace piston and/or machine cylinder bore as necessary. See appropriate CYLINDER BLOCK and PISTONS, PINS & RINGS tables under ENGINE SPECIFICATIONS. On 5.7L engines, position pistons so that arrow is facing front of engine. On 7.4L engines, position pistons so that valve cutout is pointing to centerline of engine, or dimple is facing front of engine.